21924139 has 8 divisors (see below), whose sum is σ = 22407840. Its totient is φ = 21443136.

The previous prime is 21924127. The next prime is 21924167. The reversal of 21924139 is 93142912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21924139 - 2⁵ = 21924107 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21924139.

It is not an unprimeable number, because it can be changed into a prime (21924179) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29794 + ... + 30520.

It is an arithmetic number, because the mean of its divisors is an integer number (2800980).

Almost surely, 2^21924139 is an apocalyptic number.

21924139 is a deficient number, since it is larger than the sum of its proper divisors (483701).

21924139 is an equidigital number, since it uses as much as digits as its factorization.

21924139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1349.

The product of its digits is 3888, while the sum is 31.

The square root of 21924139 is about 4682.3219667169. The cubic root of 21924139 is about 279.8814932178.

The spelling of 21924139 in words is "twenty-one million, nine hundred twenty-four thousand, one hundred thirty-nine".