21273233 has 4 divisors (see below), whose sum is σ = 21572928. Its totient is φ = 20973540.

The previous prime is 21273191. The next prime is 21273253. The reversal of 21273233 is 33237212.

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 21273233 - 2⁶ = 21273169 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21273199 and 21273208.

It is not an unprimeable number, because it can be changed into a prime (21273253) 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, 149741 + ... + 149882.

It is an arithmetic number, because the mean of its divisors is an integer number (5393232).

Almost surely, 2^21273233 is an apocalyptic number.

It is an amenable number.

21273233 is a deficient number, since it is larger than the sum of its proper divisors (299695).

21273233 is an equidigital number, since it uses as much as digits as its factorization.

21273233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299694.

The product of its digits is 1512, while the sum is 23.

The square root of 21273233 is about 4612.2915129033. The cubic root of 21273233 is about 277.0838195078.

The spelling of 21273233 in words is "twenty-one million, two hundred seventy-three thousand, two hundred thirty-three".