689661931 has 16 divisors (see below), whose sum is σ = 793748160. Its totient is φ = 586984320.

The previous prime is 689661901. The next prime is 689661937. The reversal of 689661931 is 139166986.

It is a cyclic number.

It is not a de Polignac number, because 689661931 - 2²³ = 681273323 is a prime.

It is a super-2 number, since 2×689661931² = 951267158141297522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (689661937) 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, 1018365 + ... + 1019041.

It is an arithmetic number, because the mean of its divisors is an integer number (49609260).

Almost surely, 2^689661931 is an apocalyptic number.

689661931 is a deficient number, since it is larger than the sum of its proper divisors (104086229).

689661931 is a wasteful number, since it uses less digits than its factorization.

689661931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1494.

The product of its digits is 419904, while the sum is 49.

The square root of 689661931 is about 26261.4152512769. The cubic root of 689661931 is about 883.5112514844.

The spelling of 689661931 in words is "six hundred eighty-nine million, six hundred sixty-one thousand, nine hundred thirty-one".