21893023 has 4 divisors (see below), whose sum is σ = 22358880. Its totient is φ = 21427168.

The previous prime is 21893009. The next prime is 21893051. The reversal of 21893023 is 32039812.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21893023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21892982 and 21893000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21893423) 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, 232858 + ... + 232951.

It is an arithmetic number, because the mean of its divisors is an integer number (5589720).

Almost surely, 2^21893023 is an apocalyptic number.

21893023 is a deficient number, since it is larger than the sum of its proper divisors (465857).

21893023 is an equidigital number, since it uses as much as digits as its factorization.

21893023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465856.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21893023 is about 4678.9980765117. The cubic root of 21893023 is about 279.7490225531.

The spelling of 21893023 in words is "twenty-one million, eight hundred ninety-three thousand, twenty-three".