51969691 has 4 divisors (see below), whose sum is σ = 52034584. Its totient is φ = 51904800.

The previous prime is 51969683. The next prime is 51969707. The reversal of 51969691 is 19696915.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51969691 - 2³ = 51969683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51969601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31230 + ... + 32851.

It is an arithmetic number, because the mean of its divisors is an integer number (13008646).

Almost surely, 2^51969691 is an apocalyptic number.

51969691 is a deficient number, since it is larger than the sum of its proper divisors (64893).

51969691 is an equidigital number, since it uses as much as digits as its factorization.

51969691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64892.

The product of its digits is 131220, while the sum is 46.

The square root of 51969691 is about 7209.0006935774. Note that the first 3 decimals coincide. The cubic root of 51969691 is about 373.1785832026.

The spelling of 51969691 in words is "fifty-one million, nine hundred sixty-nine thousand, six hundred ninety-one".