21624396 has 24 divisors (see below), whose sum is σ = 50541120. Its totient is φ = 7196112.

The previous prime is 21624377. The next prime is 21624397. The reversal of 21624396 is 69342612.

It is a super-2 number, since 2×21624396² = 935229004729632, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21624397) 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 7 ways as a sum of consecutive naturals, for example, 8835 + ... + 11013.

It is an arithmetic number, because the mean of its divisors is an integer number (2105880).

Almost surely, 2^21624396 is an apocalyptic number.

It is an amenable number.

21624396 is an abundant number, since it is smaller than the sum of its proper divisors (28916724).

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

21624396 is a wasteful number, since it uses less digits than its factorization.

21624396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3013 (or 3011 counting only the distinct ones).

The product of its digits is 15552, while the sum is 33.

The square root of 21624396 is about 4650.2038664988. The cubic root of 21624396 is about 278.6001389025.

The spelling of 21624396 in words is "twenty-one million, six hundred twenty-four thousand, three hundred ninety-six".