21873263 has 8 divisors (see below), whose sum is σ = 22258800. Its totient is φ = 21491008.

The previous prime is 21873251. The next prime is 21873277. The reversal of 21873263 is 36237812.

It is a happy number.

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

It is not a de Polignac number, because 21873263 - 2¹⁶ = 21807727 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 (21873233) 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, 15245 + ... + 16617.

It is an arithmetic number, because the mean of its divisors is an integer number (2782350).

Almost surely, 2^21873263 is an apocalyptic number.

21873263 is a deficient number, since it is larger than the sum of its proper divisors (385537).

21873263 is a wasteful number, since it uses less digits than its factorization.

21873263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1641.

The product of its digits is 12096, while the sum is 32.

The square root of 21873263 is about 4676.8860366701. The cubic root of 21873263 is about 279.6648327999.

The spelling of 21873263 in words is "twenty-one million, eight hundred seventy-three thousand, two hundred sixty-three".