51440031 has 12 divisors (see below), whose sum is σ = 74379760. Its totient is φ = 34257600.

The previous prime is 51440023. The next prime is 51440047. The reversal of 51440031 is 13004415.

It is a happy number.

It is not a de Polignac number, because 51440031 - 2³ = 51440023 is a prime.

It is a super-2 number, since 2×51440031² = 5292153578561922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51439986 and 51440013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51440021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8430 + ... + 13188.

Almost surely, 2^51440031 is an apocalyptic number.

51440031 is a deficient number, since it is larger than the sum of its proper divisors (22939729).

51440031 is a wasteful number, since it uses less digits than its factorization.

51440031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5966 (or 5963 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 51440031 is about 7172.1705919477. The cubic root of 51440031 is about 371.9064757954.

Adding to 51440031 its reverse (13004415), we get a palindrome (64444446).

The spelling of 51440031 in words is "fifty-one million, four hundred forty thousand, thirty-one".