51155600981 has 2 divisors, whose sum is σ = 51155600982. Its totient is φ = 51155600980.

The previous prime is 51155600963. The next prime is 51155601019. The reversal of 51155600981 is 18900655115.

51155600981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48297094756 + 2858506225 = 219766^2 + 53465^2 .

It is a cyclic number.

It is not a de Polignac number, because 51155600981 - 2¹⁸ = 51155338837 is a prime.

It is a super-2 number, since 2×51155600981² (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 (51155600281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25577800490 + 25577800491.

It is an arithmetic number, because the mean of its divisors is an integer number (25577800491).

Almost surely, 2^51155600981 is an apocalyptic number.

It is an amenable number.

51155600981 is a deficient number, since it is larger than the sum of its proper divisors (1).

51155600981 is an equidigital number, since it uses as much as digits as its factorization.

51155600981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54000, while the sum is 41.

The spelling of 51155600981 in words is "fifty-one billion, one hundred fifty-five million, six hundred thousand, nine hundred eighty-one".