51531761 has 4 divisors (see below), whose sum is σ = 51554724. Its totient is φ = 51508800.

The previous prime is 51531757. The next prime is 51531769. The reversal of 51531761 is 16713515.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16200625 + 35331136 = 4025^2 + 5944^2 .

It is a cyclic number.

It is not a de Polignac number, because 51531761 - 2² = 51531757 is a prime.

It is a super-2 number, since 2×51531761² = 5311044783522242, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51531769) 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, 7700 + ... + 12741.

It is an arithmetic number, because the mean of its divisors is an integer number (12888681).

Almost surely, 2^51531761 is an apocalyptic number.

It is an amenable number.

51531761 is a deficient number, since it is larger than the sum of its proper divisors (22963).

51531761 is a wasteful number, since it uses less digits than its factorization.

51531761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22962.

The product of its digits is 3150, while the sum is 29.

The square root of 51531761 is about 7178.5625998524. The cubic root of 51531761 is about 372.1274108792.

The spelling of 51531761 in words is "fifty-one million, five hundred thirty-one thousand, seven hundred sixty-one".