51636661553 has 2 divisors, whose sum is σ = 51636661554. Its totient is φ = 51636661552.

The previous prime is 51636661523. The next prime is 51636661561. The reversal of 51636661553 is 35516663615.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41157454129 + 10479207424 = 202873^2 + 102368^2 .

It is a cyclic number.

It is not a de Polignac number, because 51636661553 - 2³⁴ = 34456792369 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 51636661498 and 51636661507.

It is not a weakly prime, because it can be changed into another prime (51636661523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25818330776 + 25818330777.

It is an arithmetic number, because the mean of its divisors is an integer number (25818330777).

Almost surely, 2^51636661553 is an apocalyptic number.

It is an amenable number.

51636661553 is a deficient number, since it is larger than the sum of its proper divisors (1).

51636661553 is an equidigital number, since it uses as much as digits as its factorization.

51636661553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1458000, while the sum is 47.

The spelling of 51636661553 in words is "fifty-one billion, six hundred thirty-six million, six hundred sixty-one thousand, five hundred fifty-three".