688664340 has 144 divisors (see below), whose sum is σ = 2571074688. Its totient is φ = 145297152.

The previous prime is 688664323. The next prime is 688664357. The reversal of 688664340 is 43466886.

It is an interprime number because it is at equal distance from previous prime (688664323) and next prime (688664357).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4642 + ... + 37401.

Almost surely, 2^688664340 is an apocalyptic number.

688664340 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688664340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1285537344).

688664340 is an abundant number, since it is smaller than the sum of its proper divisors (1882410348).

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

688664340 is a wasteful number, since it uses less digits than its factorization.

688664340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42078 (or 42073 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The square root of 688664340 is about 26242.4149041204. The cubic root of 688664340 is about 883.0850483712.

The spelling of 688664340 in words is "six hundred eighty-eight million, six hundred sixty-four thousand, three hundred forty".