691117920 has 120 divisors (see below), whose sum is σ = 2439116064. Its totient is φ = 184294656.

The previous prime is 691117907. The next prime is 691117957. The reversal of 691117920 is 29711196.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13704 + ... + 39623.

Almost surely, 2^691117920 is an apocalyptic number.

691117920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

691117920 is an abundant number, since it is smaller than the sum of its proper divisors (1747998144).

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

691117920 is a wasteful number, since it uses less digits than its factorization.

691117920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53354 (or 53337 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 36.

The square root of 691117920 is about 26289.1217046139. The cubic root of 691117920 is about 884.1325599890.

The spelling of 691117920 in words is "six hundred ninety-one million, one hundred seventeen thousand, nine hundred twenty".