687121588 has 6 divisors (see below), whose sum is σ = 1202462786. Its totient is φ = 343560792.

The previous prime is 687121537. The next prime is 687121601. The reversal of 687121588 is 885121786.

It can be written as a sum of positive squares in only one way, i.e., 474019984 + 213101604 = 21772^2 + 14598^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85890195 + ... + 85890202.

Almost surely, 2^687121588 is an apocalyptic number.

It is an amenable number.

687121588 is a deficient number, since it is larger than the sum of its proper divisors (515341198).

687121588 is a wasteful number, since it uses less digits than its factorization.

687121588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171780401 (or 171780399 counting only the distinct ones).

The product of its digits is 215040, while the sum is 46.

The square root of 687121588 is about 26213.0041773163. The cubic root of 687121588 is about 882.4251236673.

The spelling of 687121588 in words is "six hundred eighty-seven million, one hundred twenty-one thousand, five hundred eighty-eight".