51420113531 has 4 divisors (see below), whose sum is σ = 51429565992. Its totient is φ = 51410661072.

The previous prime is 51420113501. The next prime is 51420113593. The reversal of 51420113531 is 13531102415.

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

It is a cyclic number.

It is not a de Polignac number, because 51420113531 - 2³⁴ = 34240244347 is a prime.

It is a super-2 number, since 2×51420113531² (a number of 22 digits) 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 51420113531.

It is not an unprimeable number, because it can be changed into a prime (51420113501) 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, 4718066 + ... + 4728951.

It is an arithmetic number, because the mean of its divisors is an integer number (12857391498).

Almost surely, 2^51420113531 is an apocalyptic number.

51420113531 is a deficient number, since it is larger than the sum of its proper divisors (9452461).

51420113531 is an equidigital number, since it uses as much as digits as its factorization.

51420113531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9452460.

The product of its (nonzero) digits is 1800, while the sum is 26.

Adding to 51420113531 its reverse (13531102415), we get a palindrome (64951215946).

The spelling of 51420113531 in words is "fifty-one billion, four hundred twenty million, one hundred thirteen thousand, five hundred thirty-one".