680721520 has 40 divisors (see below), whose sum is σ = 1585527984. Its totient is φ = 271798272.

The previous prime is 680721511. The next prime is 680721557. The reversal of 680721520 is 25127086.

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

It is a super-2 number, since 2×680721520² = 926763575582220800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38787 + ... + 53533.

Almost surely, 2^680721520 is an apocalyptic number.

It is an amenable number.

680721520 is an abundant number, since it is smaller than the sum of its proper divisors (904806464).

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

680721520 is a wasteful number, since it uses less digits than its factorization.

680721520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15337 (or 15331 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 680721520 is about 26090.6404674167. The cubic root of 680721520 is about 879.6768441543.

The spelling of 680721520 in words is "six hundred eighty million, seven hundred twenty-one thousand, five hundred twenty".