687121984 has 28 divisors (see below), whose sum is σ = 1383867184. Its totient is φ = 338431104.

The previous prime is 687121979. The next prime is 687121991. The reversal of 687121984 is 489121786.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75834 + ... + 84409.

It is an arithmetic number, because the mean of its divisors is an integer number (49423828).

Almost surely, 2^687121984 is an apocalyptic number.

687121984 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

687121984 is an abundant number, since it is smaller than the sum of its proper divisors (696745200).

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

687121984 is a wasteful number, since it uses less digits than its factorization.

687121984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160322 (or 160312 counting only the distinct ones).

The product of its digits is 193536, while the sum is 46.

The square root of 687121984 is about 26213.0117308180. The cubic root of 687121984 is about 882.4252931862.

The spelling of 687121984 in words is "six hundred eighty-seven million, one hundred twenty-one thousand, nine hundred eighty-four".