51505531117 has 2 divisors, whose sum is σ = 51505531118. Its totient is φ = 51505531116.

The previous prime is 51505531087. The next prime is 51505531153. The reversal of 51505531117 is 71113550515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50203331721 + 1302199396 = 224061^2 + 36086^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51505531117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51505561117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25752765558 + 25752765559.

It is an arithmetic number, because the mean of its divisors is an integer number (25752765559).

Almost surely, 2^51505531117 is an apocalyptic number.

It is an amenable number.

51505531117 is a deficient number, since it is larger than the sum of its proper divisors (1).

51505531117 is an equidigital number, since it uses as much as digits as its factorization.

51505531117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13125, while the sum is 34.

The spelling of 51505531117 in words is "fifty-one billion, five hundred five million, five hundred thirty-one thousand, one hundred seventeen".