21989272 has 8 divisors (see below), whose sum is σ = 41229900. Its totient is φ = 10994632.

The previous prime is 21989269. The next prime is 21989281. The reversal of 21989272 is 27298912.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1374322 + ... + 1374337.

Almost surely, 2^21989272 is an apocalyptic number.

It is an amenable number.

21989272 is a deficient number, since it is larger than the sum of its proper divisors (19240628).

21989272 is a wasteful number, since it uses less digits than its factorization.

21989272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2748665 (or 2748661 counting only the distinct ones).

The product of its digits is 36288, while the sum is 40.

The square root of 21989272 is about 4689.2720117306. The cubic root of 21989272 is about 280.1583797846.

The spelling of 21989272 in words is "twenty-one million, nine hundred eighty-nine thousand, two hundred seventy-two".