21733939 has 4 divisors (see below), whose sum is σ = 23012424. Its totient is φ = 20455456.

The previous prime is 21733913. The next prime is 21733969. The reversal of 21733939 is 93933712.

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 21733939 - 2¹¹ = 21731891 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21733898 and 21733907.

It is not an unprimeable number, because it can be changed into a prime (21733909) 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, 639217 + ... + 639250.

It is an arithmetic number, because the mean of its divisors is an integer number (5753106).

Almost surely, 2^21733939 is an apocalyptic number.

21733939 is a deficient number, since it is larger than the sum of its proper divisors (1278485).

21733939 is a wasteful number, since it uses less digits than its factorization.

21733939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1278484.

The product of its digits is 30618, while the sum is 37.

The square root of 21733939 is about 4661.9672886025. The cubic root of 21733939 is about 279.0697829497.

The spelling of 21733939 in words is "twenty-one million, seven hundred thirty-three thousand, nine hundred thirty-nine".