21093023 has 4 divisors (see below), whose sum is σ = 24106320. Its totient is φ = 18079728.

The previous prime is 21093019. The next prime is 21093029. The reversal of 21093023 is 32039012.

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 21093023 - 2² = 21093019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21092986 and 21093004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21093029) 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, 1506638 + ... + 1506651.

It is an arithmetic number, because the mean of its divisors is an integer number (6026580).

Almost surely, 2^21093023 is an apocalyptic number.

21093023 is a deficient number, since it is larger than the sum of its proper divisors (3013297).

21093023 is an equidigital number, since it uses as much as digits as its factorization.

21093023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3013296.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 21093023 is about 4592.7141213013. The cubic root of 21093023 is about 276.2991880909.

The spelling of 21093023 in words is "twenty-one million, ninety-three thousand, twenty-three".