21924513 has 40 divisors (see below), whose sum is σ = 36102528. Its totient is φ = 13175136.

The previous prime is 21924503. The next prime is 21924517. The reversal of 21924513 is 31542912.

It is not a de Polignac number, because 21924513 - 2⁵ = 21924481 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21924517) 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 in 39 ways as a sum of consecutive naturals, for example, 49270 + ... + 49712.

Almost surely, 2^21924513 is an apocalyptic number.

It is an amenable number.

21924513 is a deficient number, since it is larger than the sum of its proper divisors (14178015).

21924513 is a wasteful number, since it uses less digits than its factorization.

21924513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515 (or 506 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 21924513 is about 4682.3619039967. The cubic root of 21924513 is about 279.8830846917.

The spelling of 21924513 in words is "twenty-one million, nine hundred twenty-four thousand, five hundred thirteen".