51109339961 has 2 divisors, whose sum is σ = 51109339962. Its totient is φ = 51109339960.

The previous prime is 51109339951. The next prime is 51109340021. The reversal of 51109339961 is 16993390115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43323924736 + 7785415225 = 208144^2 + 88235^2 .

It is a cyclic number.

It is not a de Polignac number, because 51109339961 - 2¹⁰ = 51109338937 is a prime.

It is a super-2 number, since 2×51109339961² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51109339951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25554669980 + 25554669981.

It is an arithmetic number, because the mean of its divisors is an integer number (25554669981).

Almost surely, 2^51109339961 is an apocalyptic number.

It is an amenable number.

51109339961 is a deficient number, since it is larger than the sum of its proper divisors (1).

51109339961 is an equidigital number, since it uses as much as digits as its factorization.

51109339961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 196830, while the sum is 47.

The spelling of 51109339961 in words is "fifty-one billion, one hundred nine million, three hundred thirty-nine thousand, nine hundred sixty-one".