51243931 has 16 divisors (see below), whose sum is σ = 56736000. Its totient is φ = 46065888.

The previous prime is 51243911. The next prime is 51243937. The reversal of 51243931 is 13934215.

It is a cyclic number.

It is not a de Polignac number, because 51243931 - 2⁹ = 51243419 is a prime.

It is a super-2 number, since 2×51243931² = 5251880928665522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51243931.

It is not an unprimeable number, because it can be changed into a prime (51243937) 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, 64720 + ... + 65506.

It is an arithmetic number, because the mean of its divisors is an integer number (3546000).

Almost surely, 2^51243931 is an apocalyptic number.

51243931 is a deficient number, since it is larger than the sum of its proper divisors (5492069).

51243931 is a wasteful number, since it uses less digits than its factorization.

51243931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 978.

The product of its digits is 3240, while the sum is 28.

The square root of 51243931 is about 7158.4866417421. The cubic root of 51243931 is about 371.4332792655.

The spelling of 51243931 in words is "fifty-one million, two hundred forty-three thousand, nine hundred thirty-one".