51564450121 has 2 divisors, whose sum is σ = 51564450122. Its totient is φ = 51564450120.

The previous prime is 51564450101. The next prime is 51564450139. The reversal of 51564450121 is 12105446515.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39778308025 + 11786142096 = 199445^2 + 108564^2 .

It is a cyclic number.

It is not a de Polignac number, because 51564450121 - 2⁵ = 51564450089 is a prime.

It is not a weakly prime, because it can be changed into another prime (51564450101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25782225060 + 25782225061.

It is an arithmetic number, because the mean of its divisors is an integer number (25782225061).

Almost surely, 2^51564450121 is an apocalyptic number.

It is an amenable number.

51564450121 is a deficient number, since it is larger than the sum of its proper divisors (1).

51564450121 is an equidigital number, since it uses as much as digits as its factorization.

51564450121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24000, while the sum is 34.

Adding to 51564450121 its reverse (12105446515), we get a palindrome (63669896636).

The spelling of 51564450121 in words is "fifty-one billion, five hundred sixty-four million, four hundred fifty thousand, one hundred twenty-one".