51972138461 has 2 divisors, whose sum is σ = 51972138462. Its totient is φ = 51972138460.

The previous prime is 51972138437. The next prime is 51972138553. The reversal of 51972138461 is 16483127915.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38570603236 + 13401535225 = 196394^2 + 115765^2 .

It is a cyclic number.

It is not a de Polignac number, because 51972138461 - 2²² = 51967944157 is a prime.

It is a super-2 number, since 2×51972138461² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51972131461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25986069230 + 25986069231.

It is an arithmetic number, because the mean of its divisors is an integer number (25986069231).

Almost surely, 2^51972138461 is an apocalyptic number.

It is an amenable number.

51972138461 is a deficient number, since it is larger than the sum of its proper divisors (1).

51972138461 is an equidigital number, since it uses as much as digits as its factorization.

51972138461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 47.

The spelling of 51972138461 in words is "fifty-one billion, nine hundred seventy-two million, one hundred thirty-eight thousand, four hundred sixty-one".