687590882521 has 3 divisors (see below), whose sum is σ = 687591711733. Its totient is φ = 687590053310.

The previous prime is 687590882501. The next prime is 687590882567. The reversal of 687590882521 is 125288095786.

The square root of 687590882521 is 829211.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 687590882521 - 2⁹ = 687590882009 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 687590882521.

It is not an unprimeable number, because it can be changed into a prime (687590882501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 414606 + ... + 1243816.

Almost surely, 2^687590882521 is an apocalyptic number.

687590882521 is the 829211-st square number.

687590882521 is the 414606-th centered octagonal number.

It is an amenable number.

687590882521 is a deficient number, since it is larger than the sum of its proper divisors (829212).

687590882521 is an frugal number, since it uses more digits than its factorization.

687590882521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1658422 (or 829211 counting only the distinct ones).

The product of its (nonzero) digits is 19353600, while the sum is 61.

The spelling of 687590882521 in words is "six hundred eighty-seven billion, five hundred ninety million, eight hundred eighty-two thousand, five hundred twenty-one".