687697920 has 624 divisors, whose sum is σ = 3005376192. Its totient is φ = 141557760.

The previous prime is 687697897. The next prime is 687697939. The reversal of 687697920 is 29796786.

It is a tau number, because it is divible by the number of its divisors (624).

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, 16773100 + ... + 16773140.

It is an arithmetic number, because the mean of its divisors is an integer number (4816308).

Almost surely, 2^687697920 is an apocalyptic number.

687697920 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 687697920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1502688096).

687697920 is an abundant number, since it is smaller than the sum of its proper divisors (2317678272).

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

687697920 is a wasteful number, since it uses less digits than its factorization.

687697920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 54.

The square root of 687697920 is about 26223.9951189745. The cubic root of 687697920 is about 882.6717698318.

The spelling of 687697920 in words is "six hundred eighty-seven million, six hundred ninety-seven thousand, nine hundred twenty".