21738992 has 20 divisors (see below), whose sum is σ = 45948696. Its totient is φ = 9881280.

The previous prime is 21738989. The next prime is 21739001. The reversal of 21738992 is 29983712.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61583 + ... + 61934.

Almost surely, 2^21738992 is an apocalyptic number.

21738992 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21738992 is an abundant number, since it is smaller than the sum of its proper divisors (24209704).

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

21738992 is a wasteful number, since it uses less digits than its factorization.

21738992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123536 (or 123530 counting only the distinct ones).

The product of its digits is 54432, while the sum is 41.

The square root of 21738992 is about 4662.5091957014. The cubic root of 21738992 is about 279.0914085793.

The spelling of 21738992 in words is "twenty-one million, seven hundred thirty-eight thousand, nine hundred ninety-two".