21938361 has 16 divisors (see below), whose sum is σ = 29933568. Its totient is φ = 14288400.

The previous prime is 21938353. The next prime is 21938377. The reversal of 21938361 is 16383912.

It is not a de Polignac number, because 21938361 - 2³ = 21938353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21931361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26646 + ... + 27456.

It is an arithmetic number, because the mean of its divisors is an integer number (1870848).

Almost surely, 2^21938361 is an apocalyptic number.

It is an amenable number.

21938361 is a deficient number, since it is larger than the sum of its proper divisors (7995207).

21938361 is a wasteful number, since it uses less digits than its factorization.

21938361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1012.

The product of its digits is 7776, while the sum is 33.

The square root of 21938361 is about 4683.8404114572. The cubic root of 21938361 is about 279.9419990406.

The spelling of 21938361 in words is "twenty-one million, nine hundred thirty-eight thousand, three hundred sixty-one".