21937433 has 4 divisors (see below), whose sum is σ = 25071360. Its totient is φ = 18803508.

The previous prime is 21937417. The next prime is 21937441. The reversal of 21937433 is 33473912.

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 21937433 - 2⁴ = 21937417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21937433.

It is not an unprimeable number, because it can be changed into a prime (21937493) 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, 1566953 + ... + 1566966.

It is an arithmetic number, because the mean of its divisors is an integer number (6267840).

Almost surely, 2^21937433 is an apocalyptic number.

It is an amenable number.

21937433 is a deficient number, since it is larger than the sum of its proper divisors (3133927).

21937433 is an equidigital number, since it uses as much as digits as its factorization.

21937433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3133926.

The product of its digits is 13608, while the sum is 32.

The square root of 21937433 is about 4683.7413464025. The cubic root of 21937433 is about 279.9380517715.

The spelling of 21937433 in words is "twenty-one million, nine hundred thirty-seven thousand, four hundred thirty-three".