51313531 has 8 divisors (see below), whose sum is σ = 54465264. Its totient is φ = 48176640.

The previous prime is 51313517. The next prime is 51313553. The reversal of 51313531 is 13531315.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51313531 - 2⁷ = 51313403 is a prime.

It is a super-2 number, since 2×51313531² = 5266156927375922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51313501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3876 + ... + 10846.

It is an arithmetic number, because the mean of its divisors is an integer number (6808158).

Almost surely, 2^51313531 is an apocalyptic number.

51313531 is a deficient number, since it is larger than the sum of its proper divisors (3151733).

51313531 is a wasteful number, since it uses less digits than its factorization.

51313531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7421.

The product of its digits is 675, while the sum is 22.

The square root of 51313531 is about 7163.3463548819. The cubic root of 51313531 is about 371.6013646076.

Adding to 51313531 its reverse (13531315), we get a palindrome (64844846).

The spelling of 51313531 in words is "fifty-one million, three hundred thirteen thousand, five hundred thirty-one".