25684621 has 2 divisors, whose sum is σ = 25684622. Its totient is φ = 25684620.

The previous prime is 25684619. The next prime is 25684627. The reversal of 25684621 is 12648652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21436900 + 4247721 = 4630^2 + 2061^2 .

It is a cyclic number.

It is not a de Polignac number, because 25684621 - 2¹ = 25684619 is a prime.

Together with 25684619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25684627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12842310 + 12842311.

It is an arithmetic number, because the mean of its divisors is an integer number (12842311).

Almost surely, 2^25684621 is an apocalyptic number.

It is an amenable number.

25684621 is a deficient number, since it is larger than the sum of its proper divisors (1).

25684621 is an equidigital number, since it uses as much as digits as its factorization.

25684621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 34.

The square root of 25684621 is about 5067.9997040252. Note that the first 3 decimals coincide. The cubic root of 25684621 is about 295.0468986052.

The spelling of 25684621 in words is "twenty-five million, six hundred eighty-four thousand, six hundred twenty-one".