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387640 = 23511881
BaseRepresentation
bin1011110101000111000
3201200202001
41132220320
544401030
612150344
73203101
oct1365070
9650661
10387640
11245270
121683b4
13107596
14a13a8
1579cca
hex5ea38

387640 has 32 divisors (see below), whose sum is σ = 952560. Its totient is φ = 140800.

The previous prime is 387631. The next prime is 387641. The reversal of 387640 is 46783.

387640 is a nontrivial binomial coefficient, being equal to C(881, 2).

It is a junction number, because it is equal to n+sod(n) for n = 387599 and 387608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (387641) 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, 1 + ... + 880.

2387640 is an apocalyptic number.

387640 is the 880-th triangular number.

387640 is the 294-th centered nonagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 387640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (476280).

387640 is an abundant number, since it is smaller than the sum of its proper divisors (564920).

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

387640 is a wasteful number, since it uses less digits than its factorization.

387640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903 (or 899 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 387640 is about 622.6074204505. The cubic root of 387640 is about 72.9137656896.

It can be divided in two parts, 3876 and 40, that added together give a triangular number (3916 = T88).

The spelling of 387640 in words is "three hundred eighty-seven thousand, six hundred forty".

Divisors: 1 2 4 5 8 10 11 20 22 40 44 55 88 110 220 440 881 1762 3524 4405 7048 8810 9691 17620 19382 35240 38764 48455 77528 96910 193820 387640