51254500021 has 2 divisors, whose sum is σ = 51254500022. Its totient is φ = 51254500020.

The previous prime is 51254499971. The next prime is 51254500027. The reversal of 51254500021 is 12000545215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29005496100 + 22249003921 = 170310^2 + 149161^2 .

It is a cyclic number.

It is not a de Polignac number, because 51254500021 - 2⁹ = 51254499509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51254500027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25627250010 + 25627250011.

It is an arithmetic number, because the mean of its divisors is an integer number (25627250011).

Almost surely, 2^51254500021 is an apocalyptic number.

It is an amenable number.

51254500021 is a deficient number, since it is larger than the sum of its proper divisors (1).

51254500021 is an equidigital number, since it uses as much as digits as its factorization.

51254500021 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 25.

The spelling of 51254500021 in words is "fifty-one billion, two hundred fifty-four million, five hundred thousand, twenty-one".