51505023257 has 2 divisors, whose sum is σ = 51505023258. Its totient is φ = 51505023256.

The previous prime is 51505023221. The next prime is 51505023259. The reversal of 51505023257 is 75232050515.

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., 26510678041 + 24994345216 = 162821^2 + 158096^2 .

It is a cyclic number.

It is not a de Polignac number, because 51505023257 - 2²⁶ = 51437914393 is a prime.

It is a super-2 number, since 2×51505023257² (a number of 22 digits) contains 22 as substring.

Together with 51505023259, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51505023259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25752511628 + 25752511629.

It is an arithmetic number, because the mean of its divisors is an integer number (25752511629).

Almost surely, 2^51505023257 is an apocalyptic number.

It is an amenable number.

51505023257 is a deficient number, since it is larger than the sum of its proper divisors (1).

51505023257 is an equidigital number, since it uses as much as digits as its factorization.

51505023257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52500, while the sum is 35.

The spelling of 51505023257 in words is "fifty-one billion, five hundred five million, twenty-three thousand, two hundred fifty-seven".