21942456 has 16 divisors (see below), whose sum is σ = 54856200. Its totient is φ = 7314144.

The previous prime is 21942379. The next prime is 21942457. The reversal of 21942456 is 65424912.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21942457) 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, 457111 + ... + 457158.

Almost surely, 2^21942456 is an apocalyptic number.

It is an amenable number.

21942456 is an abundant number, since it is smaller than the sum of its proper divisors (32913744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21942456 is a wasteful number, since it uses less digits than its factorization.

21942456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914278 (or 914274 counting only the distinct ones).

The product of its digits is 17280, while the sum is 33.

The square root of 21942456 is about 4684.2775323416. The cubic root of 21942456 is about 279.9594158866.

The spelling of 21942456 in words is "twenty-one million, nine hundred forty-two thousand, four hundred fifty-six".