21425624 has 16 divisors (see below), whose sum is σ = 43825320. Its totient is φ = 9738880.

The previous prime is 21425603. The next prime is 21425639. The reversal of 21425624 is 42652412.

It is a junction number, because it is equal to n+sod(n) for n = 21425593 and 21425602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121649 + ... + 121824.

Almost surely, 2^21425624 is an apocalyptic number.

It is an amenable number.

21425624 is an abundant number, since it is smaller than the sum of its proper divisors (22399696).

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

21425624 is a wasteful number, since it uses less digits than its factorization.

21425624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243490 (or 243486 counting only the distinct ones).

The product of its digits is 3840, while the sum is 26.

The square root of 21425624 is about 4628.7821292431. The cubic root of 21425624 is about 277.7438767279.

The spelling of 21425624 in words is "twenty-one million, four hundred twenty-five thousand, six hundred twenty-four".