21889972 has 48 divisors (see below), whose sum is σ = 42969472. Its totient is φ = 9694080.

The previous prime is 21889963. The next prime is 21889981. The reversal of 21889972 is 27998812.

It is an interprime number because it is at equal distance from previous prime (21889963) and next prime (21889981).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 212473 + ... + 212575.

Almost surely, 2^21889972 is an apocalyptic number.

It is an amenable number.

21889972 is a deficient number, since it is larger than the sum of its proper divisors (21079500).

21889972 is a wasteful number, since it uses less digits than its factorization.

21889972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248 (or 246 counting only the distinct ones).

The product of its digits is 145152, while the sum is 46.

The square root of 21889972 is about 4678.6720338147. The cubic root of 21889972 is about 279.7360267245.

The spelling of 21889972 in words is "twenty-one million, eight hundred eighty-nine thousand, nine hundred seventy-two".