51507662500661 has 2 divisors, whose sum is σ = 51507662500662. Its totient is φ = 51507662500660.

The previous prime is 51507662500631. The next prime is 51507662500699. The reversal of 51507662500661 is 16600526670515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44047034598436 + 7460627902225 = 6636794^2 + 2731415^2 .

It is a cyclic number.

It is not a de Polignac number, because 51507662500661 - 2¹⁴ = 51507662484277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51507662500601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25753831250330 + 25753831250331.

It is an arithmetic number, because the mean of its divisors is an integer number (25753831250331).

Almost surely, 2^{51507662500661} is an apocalyptic number.

It is an amenable number.

51507662500661 is a deficient number, since it is larger than the sum of its proper divisors (1).

51507662500661 is an equidigital number, since it uses as much as digits as its factorization.

51507662500661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268000, while the sum is 50.

The spelling of 51507662500661 in words is "fifty-one trillion, five hundred seven billion, six hundred sixty-two million, five hundred thousand, six hundred sixty-one".