51400072861 has 2 divisors, whose sum is σ = 51400072862. Its totient is φ = 51400072860.

The previous prime is 51400072831. The next prime is 51400072897. The reversal of 51400072861 is 16827000415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46831124025 + 4568948836 = 216405^2 + 67594^2 .

It is a cyclic number.

It is not a de Polignac number, because 51400072861 - 2³¹ = 49252589213 is a prime.

It is a super-2 number, since 2×51400072861² (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 (51400072831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25700036430 + 25700036431.

It is an arithmetic number, because the mean of its divisors is an integer number (25700036431).

Almost surely, 2^51400072861 is an apocalyptic number.

It is an amenable number.

51400072861 is a deficient number, since it is larger than the sum of its proper divisors (1).

51400072861 is an equidigital number, since it uses as much as digits as its factorization.

51400072861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 34.

The spelling of 51400072861 in words is "fifty-one billion, four hundred million, seventy-two thousand, eight hundred sixty-one".