21969792 has 160 divisors (see below), whose sum is σ = 70843080. Its totient is φ = 6718464.

The previous prime is 21969781. The next prime is 21969811. The reversal of 21969792 is 29796912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 134703 + ... + 134865.

Almost surely, 2^21969792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21969792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35421540).

21969792 is an abundant number, since it is smaller than the sum of its proper divisors (48873288).

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

21969792 is a wasteful number, since it uses less digits than its factorization.

21969792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202 (or 181 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 21969792 is about 4687.1944700428. The cubic root of 21969792 is about 280.0756258307.

The spelling of 21969792 in words is "twenty-one million, nine hundred sixty-nine thousand, seven hundred ninety-two".