687900521 has 8 divisors (see below), whose sum is σ = 857642304. Its totient is φ = 536026320.

The previous prime is 687900517. The next prime is 687900523. The reversal of 687900521 is 125009786.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 687900521 - 2² = 687900517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687900523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4466810 + ... + 4466963.

It is an arithmetic number, because the mean of its divisors is an integer number (107205288).

Almost surely, 2^687900521 is an apocalyptic number.

It is an amenable number.

687900521 is a deficient number, since it is larger than the sum of its proper divisors (169741783).

687900521 is a wasteful number, since it uses less digits than its factorization.

687900521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8933791.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 687900521 is about 26227.8577279960. The cubic root of 687900521 is about 882.7584419104.

The spelling of 687900521 in words is "six hundred eighty-seven million, nine hundred thousand, five hundred twenty-one".