25921953210421 has 4 divisors (see below), whose sum is σ = 25956469793344. Its totient is φ = 25887436627500.

The previous prime is 25921953210313. The next prime is 25921953210427. The reversal of 25921953210421 is 12401235912952.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25921953210421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25921953210427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17258290335 + ... + 17258291836.

It is an arithmetic number, because the mean of its divisors is an integer number (6489117448336).

Almost surely, 2^{25921953210421} is an apocalyptic number.

It is an amenable number.

25921953210421 is a deficient number, since it is larger than the sum of its proper divisors (34516582923).

25921953210421 is an equidigital number, since it uses as much as digits as its factorization.

25921953210421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34516582922.

The product of its (nonzero) digits is 388800, while the sum is 46.

The spelling of 25921953210421 in words is "twenty-five trillion, nine hundred twenty-one billion, nine hundred fifty-three million, two hundred ten thousand, four hundred twenty-one".