687720320 has 64 divisors (see below), whose sum is σ = 1878962400. Its totient is φ = 235788288.

The previous prime is 687720301. The next prime is 687720323. The reversal of 687720320 is 23027786.

687720320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687720323) 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, 72275 + ... + 81234.

Almost surely, 2^687720320 is an apocalyptic number.

It is an amenable number.

687720320 is an abundant number, since it is smaller than the sum of its proper divisors (1191242080).

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

687720320 is a wasteful number, since it uses less digits than its factorization.

687720320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153535 (or 153523 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 687720320 is about 26224.4222052651. The cubic root of 687720320 is about 882.6813533192.

The spelling of 687720320 in words is "six hundred eighty-seven million, seven hundred twenty thousand, three hundred twenty".