51231231 has 16 divisors (see below), whose sum is σ = 77332320. Its totient is φ = 33508800.

The previous prime is 51231227. The next prime is 51231233. The reversal of 51231231 is 13213215.

It is not a de Polignac number, because 51231231 - 2² = 51231227 is a prime.

It is a super-2 number, since 2×51231231² = 5249278059550722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51231233) 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, 16470 + ... + 19331.

It is an arithmetic number, because the mean of its divisors is an integer number (4833270).

Almost surely, 2^51231231 is an apocalyptic number.

51231231 is a deficient number, since it is larger than the sum of its proper divisors (26101089).

51231231 is a wasteful number, since it uses less digits than its factorization.

51231231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35863 (or 35857 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 51231231 is about 7157.5995277747. The cubic root of 51231231 is about 371.4025921038.

Adding to 51231231 its reverse (13213215), we get a palindrome (64444446).

The spelling of 51231231 in words is "fifty-one million, two hundred thirty-one thousand, two hundred thirty-one".