21923624 has 8 divisors (see below), whose sum is σ = 41106810. Its totient is φ = 10961808.

The previous prime is 21923621. The next prime is 21923639. The reversal of 21923624 is 42632912.

It can be written as a sum of positive squares in only one way, i.e., 21921124 + 2500 = 4682^2 + 50^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21923621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1370219 + ... + 1370234.

Almost surely, 2^21923624 is an apocalyptic number.

It is an amenable number.

21923624 is a deficient number, since it is larger than the sum of its proper divisors (19183186).

21923624 is a wasteful number, since it uses less digits than its factorization.

21923624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2740459 (or 2740455 counting only the distinct ones).

The product of its digits is 5184, while the sum is 29.

The square root of 21923624 is about 4682.2669723116. The cubic root of 21923624 is about 279.8793017201.

The spelling of 21923624 in words is "twenty-one million, nine hundred twenty-three thousand, six hundred twenty-four".