25421812421 has 2 divisors, whose sum is σ = 25421812422. Its totient is φ = 25421812420.

The previous prime is 25421812397. The next prime is 25421812483. The reversal of 25421812421 is 12421812452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21194992225 + 4226820196 = 145585^2 + 65014^2 .

It is a cyclic number.

It is not a de Polignac number, because 25421812421 - 2³⁰ = 24348070597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25421812321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12710906210 + 12710906211.

It is an arithmetic number, because the mean of its divisors is an integer number (12710906211).

Almost surely, 2^25421812421 is an apocalyptic number.

It is an amenable number.

25421812421 is a deficient number, since it is larger than the sum of its proper divisors (1).

25421812421 is an equidigital number, since it uses as much as digits as its factorization.

25421812421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10240, while the sum is 32.

The spelling of 25421812421 in words is "twenty-five billion, four hundred twenty-one million, eight hundred twelve thousand, four hundred twenty-one".