51312211331 has 4 divisors (see below), whose sum is σ = 51312702672. Its totient is φ = 51311719992.

The previous prime is 51312211303. The next prime is 51312211369. The reversal of 51312211331 is 13311221315.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 51312211331 - 2³⁴ = 34132342147 is a prime.

It is a super-2 number, since 2×51312211331² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51312211297 and 51312211306.

It is not an unprimeable number, because it can be changed into a prime (51312211831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19796 + ... + 320961.

It is an arithmetic number, because the mean of its divisors is an integer number (12828175668).

Almost surely, 2^51312211331 is an apocalyptic number.

51312211331 is a deficient number, since it is larger than the sum of its proper divisors (491341).

51312211331 is a wasteful number, since it uses less digits than its factorization.

51312211331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491340.

The product of its digits is 540, while the sum is 23.

Adding to 51312211331 its reverse (13311221315), we get a palindrome (64623432646).

The spelling of 51312211331 in words is "fifty-one billion, three hundred twelve million, two hundred eleven thousand, three hundred thirty-one".