21923029 has 4 divisors (see below), whose sum is σ = 21954240. Its totient is φ = 21891820.

The previous prime is 21923023. The next prime is 21923059. The reversal of 21923029 is 92032912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21923029 - 2³ = 21923021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21922988 and 21923006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21923021) 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, 14527 + ... + 15964.

It is an arithmetic number, because the mean of its divisors is an integer number (5488560).

Almost surely, 2^21923029 is an apocalyptic number.

It is an amenable number.

21923029 is a deficient number, since it is larger than the sum of its proper divisors (31211).

21923029 is an equidigital number, since it uses as much as digits as its factorization.

21923029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31210.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 21923029 is about 4682.2034342818. The cubic root of 21923029 is about 279.8767697529.

The spelling of 21923029 in words is "twenty-one million, nine hundred twenty-three thousand, twenty-nine".