25451236021 has 2 divisors, whose sum is σ = 25451236022. Its totient is φ = 25451236020.

The previous prime is 25451236009. The next prime is 25451236123. The reversal of 25451236021 is 12063215452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19387499121 + 6063736900 = 139239^2 + 77870^2 .

It is a cyclic number.

It is not a de Polignac number, because 25451236021 - 2¹⁷ = 25451104949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25451246021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12725618010 + 12725618011.

It is an arithmetic number, because the mean of its divisors is an integer number (12725618011).

Almost surely, 2^25451236021 is an apocalyptic number.

It is an amenable number.

25451236021 is a deficient number, since it is larger than the sum of its proper divisors (1).

25451236021 is an equidigital number, since it uses as much as digits as its factorization.

25451236021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14400, while the sum is 31.

The spelling of 25451236021 in words is "twenty-five billion, four hundred fifty-one million, two hundred thirty-six thousand, twenty-one".