687391632 has 30 divisors (see below), whose sum is σ = 1923742262. Its totient is φ = 229130496.

The previous prime is 687391577. The next prime is 687391657. The reversal of 687391632 is 236193786.

687391632 is a `hidden beast` number, since 6 + 8 + 7 + 3 + 9 + 1 + 632 = 666.

It can be written as a sum of positive squares in only one way, i.e., 429981696 + 257409936 = 20736^2 + 16044^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2386633 + ... + 2386920.

Almost surely, 2^687391632 is an apocalyptic number.

It is an amenable number.

687391632 is an abundant number, since it is smaller than the sum of its proper divisors (1236350630).

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

687391632 is a wasteful number, since it uses less digits than its factorization.

687391632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4773567 (or 4773558 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The square root of 687391632 is about 26218.1546261364. The cubic root of 687391632 is about 882.5407084507.

The spelling of 687391632 in words is "six hundred eighty-seven million, three hundred ninety-one thousand, six hundred thirty-two".