21938697 has 12 divisors (see below), whose sum is σ = 34570224. Its totient is φ = 13296120.

The previous prime is 21938663. The next prime is 21938699. The reversal of 21938697 is 79683912.

It is not a de Polignac number, because 21938697 - 2⁶ = 21938633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21938699) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 110703 + ... + 110900.

It is an arithmetic number, because the mean of its divisors is an integer number (2880852).

Almost surely, 2^21938697 is an apocalyptic number.

It is an amenable number.

21938697 is a deficient number, since it is larger than the sum of its proper divisors (12631527).

21938697 is a wasteful number, since it uses less digits than its factorization.

21938697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221620 (or 221617 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 21938697 is about 4683.8762793225. The cubic root of 21938697 is about 279.9434281967.

The spelling of 21938697 in words is "twenty-one million, nine hundred thirty-eight thousand, six hundred ninety-seven".