21938456 has 16 divisors (see below), whose sum is σ = 41383440. Its totient is φ = 10902880.

The previous prime is 21938453. The next prime is 21938459. The reversal of 21938456 is 65483912.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21938453) and next prime (21938459).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21938453) 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, 6875 + ... + 9546.

It is an arithmetic number, because the mean of its divisors is an integer number (2586465).

Almost surely, 2^21938456 is an apocalyptic number.

It is an amenable number.

21938456 is a deficient number, since it is larger than the sum of its proper divisors (19444984).

21938456 is a wasteful number, since it uses less digits than its factorization.

21938456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16594 (or 16590 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 21938456 is about 4683.8505526970. The cubic root of 21938456 is about 279.9424031189.

The spelling of 21938456 in words is "twenty-one million, nine hundred thirty-eight thousand, four hundred fifty-six".