51512400521 has 2 divisors, whose sum is σ = 51512400522. Its totient is φ = 51512400520.

The previous prime is 51512400503. The next prime is 51512400523. The reversal of 51512400521 is 12500421515.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50890396921 + 622003600 = 225589^2 + 24940^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51512400521 is a prime.

It is a Sophie Germain prime.

Together with 51512400523, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51512400523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25756200260 + 25756200261.

It is an arithmetic number, because the mean of its divisors is an integer number (25756200261).

Almost surely, 2^51512400521 is an apocalyptic number.

It is an amenable number.

51512400521 is a deficient number, since it is larger than the sum of its proper divisors (1).

51512400521 is an equidigital number, since it uses as much as digits as its factorization.

51512400521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2000, while the sum is 26.

The spelling of 51512400521 in words is "fifty-one billion, five hundred twelve million, four hundred thousand, five hundred twenty-one".