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688240 = 24571229
BaseRepresentation
bin10101000000001110000
31021222002101
42220001300
5134010430
622430144
75564350
oct2500160
91258071
10688240
114300a3
12292354
131b1357
1413cb60
15d8dca
hexa8070

688240 has 40 divisors (see below), whose sum is σ = 1830240. Its totient is φ = 235776.

The previous prime is 688223. The next prime is 688249. The reversal of 688240 is 42886.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 688199 and 688208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55 + ... + 1174.

It is an arithmetic number, because the mean of its divisors is an integer number (45756).

2688240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (915120).

688240 is an abundant number, since it is smaller than the sum of its proper divisors (1142000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

688240 is a wasteful number, since it uses less digits than its factorization.

688240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1249 (or 1243 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 688240 is about 829.6023143651. The cubic root of 688240 is about 88.2903631833.

The spelling of 688240 in words is "six hundred eighty-eight thousand, two hundred forty".

Divisors: 1 2 4 5 7 8 10 14 16 20 28 35 40 56 70 80 112 140 280 560 1229 2458 4916 6145 8603 9832 12290 17206 19664 24580 34412 43015 49160 68824 86030 98320 137648 172060 344120 688240