51565121520401 has 2 divisors, whose sum is σ = 51565121520402. Its totient is φ = 51565121520400.

The previous prime is 51565121520383. The next prime is 51565121520449. The reversal of 51565121520401 is 10402512156515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49840564246225 + 1724557274176 = 7059785^2 + 1313224^2 .

It is a cyclic number.

It is not a de Polignac number, because 51565121520401 - 2⁶ = 51565121520337 is a prime.

It is a super-3 number, since 3×51565121520401³ (a number of 42 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (51565121520491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25782560760200 + 25782560760201.

It is an arithmetic number, because the mean of its divisors is an integer number (25782560760201).

Almost surely, 2^{51565121520401} is an apocalyptic number.

It is an amenable number.

51565121520401 is a deficient number, since it is larger than the sum of its proper divisors (1).

51565121520401 is an equidigital number, since it uses as much as digits as its factorization.

51565121520401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60000, while the sum is 38.

Adding to 51565121520401 its reverse (10402512156515), we get a palindrome (61967633676916).

The spelling of 51565121520401 in words is "fifty-one trillion, five hundred sixty-five billion, one hundred twenty-one million, five hundred twenty thousand, four hundred one".