51591988633 has 2 divisors, whose sum is σ = 51591988634. Its totient is φ = 51591988632.

The previous prime is 51591988621. The next prime is 51591988681. The reversal of 51591988633 is 33688919515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41757696409 + 9834292224 = 204347^2 + 99168^2 .

It is a cyclic number.

It is not a de Polignac number, because 51591988633 - 2¹³ = 51591980441 is a prime.

It is a super-2 number, since 2×51591988633² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51591988033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25795994316 + 25795994317.

It is an arithmetic number, because the mean of its divisors is an integer number (25795994317).

Almost surely, 2^51591988633 is an apocalyptic number.

It is an amenable number.

51591988633 is a deficient number, since it is larger than the sum of its proper divisors (1).

51591988633 is an equidigital number, since it uses as much as digits as its factorization.

51591988633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6998400, while the sum is 58.

The spelling of 51591988633 in words is "fifty-one billion, five hundred ninety-one million, nine hundred eighty-eight thousand, six hundred thirty-three".