687638730 has 16 divisors (see below), whose sum is σ = 1650333024. Its totient is φ = 183370320.

The previous prime is 687638711. The next prime is 687638737. The reversal of 687638730 is 37836786.

It is a self number, because there is not a number n which added to its sum of digits gives 687638730.

It is not an unprimeable number, because it can be changed into a prime (687638737) 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, 11460616 + ... + 11460675.

It is an arithmetic number, because the mean of its divisors is an integer number (103145814).

Almost surely, 2^687638730 is an apocalyptic number.

687638730 is an abundant number, since it is smaller than the sum of its proper divisors (962694294).

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

687638730 is a wasteful number, since it uses less digits than its factorization.

687638730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22921301.

The product of its (nonzero) digits is 1016064, while the sum is 48.

The square root of 687638730 is about 26222.8665481103. The cubic root of 687638730 is about 882.6464453206.

The spelling of 687638730 in words is "six hundred eighty-seven million, six hundred thirty-eight thousand, seven hundred thirty".