21923039 has 4 divisors (see below), whose sum is σ = 22187256. Its totient is φ = 21658824.

The previous prime is 21923023. The next prime is 21923059. The reversal of 21923039 is 93032912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21923039 - 2⁴ = 21923023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21923059) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131984 + ... + 132149.

It is an arithmetic number, because the mean of its divisors is an integer number (5546814).

Almost surely, 2^21923039 is an apocalyptic number.

21923039 is a deficient number, since it is larger than the sum of its proper divisors (264217).

21923039 is an equidigital number, since it uses as much as digits as its factorization.

21923039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264216.

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 21923039 is about 4682.2045021549. The cubic root of 21923039 is about 279.8768123074.

The spelling of 21923039 in words is "twenty-one million, nine hundred twenty-three thousand, thirty-nine".