51520875491 has 2 divisors, whose sum is σ = 51520875492. Its totient is φ = 51520875490.

The previous prime is 51520875487. The next prime is 51520875509. The reversal of 51520875491 is 19457802515.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51520875491 - 2² = 51520875487 is a prime.

It is a super-2 number, since 2×51520875491² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51520875401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25760437745 + 25760437746.

It is an arithmetic number, because the mean of its divisors is an integer number (25760437746).

Almost surely, 2^51520875491 is an apocalyptic number.

51520875491 is a deficient number, since it is larger than the sum of its proper divisors (1).

51520875491 is an equidigital number, since it uses as much as digits as its factorization.

51520875491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504000, while the sum is 47.

The spelling of 51520875491 in words is "fifty-one billion, five hundred twenty million, eight hundred seventy-five thousand, four hundred ninety-one".