21994272 has 36 divisors (see below), whose sum is σ = 62547030. Its totient is φ = 7331328.

The previous prime is 21994237. The next prime is 21994319. The reversal of 21994272 is 27249912.

It can be written as a sum of positive squares in only one way, i.e., 20466576 + 1527696 = 4524^2 + 1236^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37897 + ... + 38472.

Almost surely, 2^21994272 is an apocalyptic number.

It is an amenable number.

21994272 is an abundant number, since it is smaller than the sum of its proper divisors (40552758).

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

21994272 is a wasteful number, since it uses less digits than its factorization.

21994272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76385 (or 76374 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 21994272 is about 4689.8051132217. The cubic root of 21994272 is about 280.1796126497.

The spelling of 21994272 in words is "twenty-one million, nine hundred ninety-four thousand, two hundred seventy-two".