21908272 has 20 divisors (see below), whose sum is σ = 43145056. Its totient is φ = 10774080.

The previous prime is 21908269. The next prime is 21908279. The reversal of 21908272 is 27280912.

It is not an unprimeable number, because it can be changed into a prime (21908279) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10248 + ... + 12199.

Almost surely, 2^21908272 is an apocalyptic number.

It is an amenable number.

21908272 is a deficient number, since it is larger than the sum of its proper divisors (21236784).

21908272 is a wasteful number, since it uses less digits than its factorization.

21908272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22516 (or 22510 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21908272 is about 4680.6273083851. The cubic root of 21908272 is about 279.8139580471.

The spelling of 21908272 in words is "twenty-one million, nine hundred eight thousand, two hundred seventy-two".