687163988 has 24 divisors (see below), whose sum is σ = 1377540864. Its totient is φ = 293810400.

The previous prime is 687163979. The next prime is 687164003. The reversal of 687163988 is 889361786.

It is a happy number.

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, 16403 + ... + 40538.

It is an arithmetic number, because the mean of its divisors is an integer number (57397536).

Almost surely, 2^687163988 is an apocalyptic number.

It is an amenable number.

687163988 is an abundant number, since it is smaller than the sum of its proper divisors (690376876).

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

687163988 is a wasteful number, since it uses less digits than its factorization.

687163988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57383 (or 57381 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 56.

The square root of 687163988 is about 26213.8129237240. The cubic root of 687163988 is about 882.4432738056.

The spelling of 687163988 in words is "six hundred eighty-seven million, one hundred sixty-three thousand, nine hundred eighty-eight".