51312131 has 4 divisors (see below), whose sum is σ = 55259232. Its totient is φ = 47365032.

The previous prime is 51312119. The next prime is 51312133. The reversal of 51312131 is 13121315.

51312131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13121315 = 5 ⋅2624263.

It is a de Polignac number, because none of the positive numbers 2^k-51312131 is a prime.

It is a super-2 number, since 2×51312131² = 5265869575522322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51312133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1973531 + ... + 1973556.

It is an arithmetic number, because the mean of its divisors is an integer number (13814808).

Almost surely, 2^51312131 is an apocalyptic number.

51312131 is a deficient number, since it is larger than the sum of its proper divisors (3947101).

51312131 is a wasteful number, since it uses less digits than its factorization.

51312131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3947100.

The product of its digits is 90, while the sum is 17.

The square root of 51312131 is about 7163.2486345233. The cubic root of 51312131 is about 371.5979850790.

Adding to 51312131 its reverse (13121315), we get a palindrome (64433446).

The spelling of 51312131 in words is "fifty-one million, three hundred twelve thousand, one hundred thirty-one".