25623621 has 14 divisors (see below), whose sum is σ = 38418950. Its totient is φ = 17081928.

The previous prime is 25623613. The next prime is 25623649. The reversal of 25623621 is 12632652.

It can be written as a sum of positive squares in only one way, i.e., 24147396 + 1476225 = 4914^2 + 1215^2 .

It is not a de Polignac number, because 25623621 - 2³ = 25623613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25623691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 16846 + ... + 18303.

Almost surely, 2^25623621 is an apocalyptic number.

It is an amenable number.

25623621 is a deficient number, since it is larger than the sum of its proper divisors (12795329).

25623621 is an frugal number, since it uses more digits than its factorization.

25623621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35167 (or 35152 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 25623621 is about 5061.9779730852. The cubic root of 25623621 is about 294.8131383884.

It can be divided in two parts, 25623 and 621, that added together give a square (26244 = 162²).

The spelling of 25623621 in words is "twenty-five million, six hundred twenty-three thousand, six hundred twenty-one".