51931981951 has 2 divisors, whose sum is σ = 51931981952. Its totient is φ = 51931981950.

The previous prime is 51931981943. The next prime is 51931981967. The reversal of 51931981951 is 15918913915.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51931981951 - 2³ = 51931981943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51931981901) 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 as a sum of consecutive naturals, namely, 25965990975 + 25965990976.

It is an arithmetic number, because the mean of its divisors is an integer number (25965990976).

Almost surely, 2^51931981951 is an apocalyptic number.

51931981951 is a deficient number, since it is larger than the sum of its proper divisors (1).

51931981951 is an equidigital number, since it uses as much as digits as its factorization.

51931981951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 437400, while the sum is 52.

The spelling of 51931981951 in words is "fifty-one billion, nine hundred thirty-one million, nine hundred eighty-one thousand, nine hundred fifty-one".