687631388257 has 16 divisors (see below), whose sum is σ = 755820704448. Its totient is φ = 620401151680.

The previous prime is 687631388251. The next prime is 687631388293. The reversal of 687631388257 is 752883136786.

It is a cyclic number.

It is not a de Polignac number, because 687631388257 - 2¹¹ = 687631386209 is a prime.

It is a super-2 number, since 2×687631388257² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687631388251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 750483 + ... + 1392295.

It is an arithmetic number, because the mean of its divisors is an integer number (47238794028).

Almost surely, 2^687631388257 is an apocalyptic number.

It is an amenable number.

687631388257 is a deficient number, since it is larger than the sum of its proper divisors (68189316191).

687631388257 is a wasteful number, since it uses less digits than its factorization.

687631388257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642560.

The product of its digits is 81285120, while the sum is 64.

The spelling of 687631388257 in words is "six hundred eighty-seven billion, six hundred thirty-one million, three hundred eighty-eight thousand, two hundred fifty-seven".