21589425 has 108 divisors (see below), whose sum is σ = 46523932. Its totient is φ = 9504000.

The previous prime is 21589409. The next prime is 21589459. The reversal of 21589425 is 52498512.

It can be written as a sum of positive squares in 6 ways, for example, as 7683984 + 13905441 = 2772^2 + 3729^2 .

It is not a de Polignac number, because 21589425 - 2⁴ = 21589409 is a prime.

It is a super-2 number, since 2×21589425² = 932206543661250, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21589425.

It is a congruent number.

It is an unprimeable number.

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 107 ways as a sum of consecutive naturals, for example, 353895 + ... + 353955.

Almost surely, 2^21589425 is an apocalyptic number.

21589425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21589425 is an abundant number, since it is smaller than the sum of its proper divisors (24934507).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21589425 is a wasteful number, since it uses less digits than its factorization.

21589425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112 (or 93 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 21589425 is about 4646.4421873085. The cubic root of 21589425 is about 278.4498737071.

The spelling of 21589425 in words is "twenty-one million, five hundred eighty-nine thousand, four hundred twenty-five".