21624124 has 12 divisors (see below), whose sum is σ = 38023048. Its totient is φ = 10760400.

The previous prime is 21624107. The next prime is 21624137. The reversal of 21624124 is 42142612.

It is a happy number.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21624095 and 21624104.

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, 11967 + ... + 13654.

Almost surely, 2^21624124 is an apocalyptic number.

It is an amenable number.

21624124 is a deficient number, since it is larger than the sum of its proper divisors (16398924).

21624124 is a wasteful number, since it uses less digits than its factorization.

21624124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25836 (or 25834 counting only the distinct ones).

The product of its digits is 768, while the sum is 22.

The square root of 21624124 is about 4650.1746203772. The cubic root of 21624124 is about 278.5989707842.

Adding to 21624124 its reverse (42142612), we get a palindrome (63766736).

The spelling of 21624124 in words is "twenty-one million, six hundred twenty-four thousand, one hundred twenty-four".