21612472 has 32 divisors (see below), whose sum is σ = 46609920. Its totient is φ = 9203040.

The previous prime is 21612431. The next prime is 21612497. The reversal of 21612472 is 27421612.

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 in 7 ways as a sum of consecutive naturals, for example, 8197 + ... + 10507.

It is an arithmetic number, because the mean of its divisors is an integer number (1456560).

Almost surely, 2^21612472 is an apocalyptic number.

It is an amenable number.

21612472 is an abundant number, since it is smaller than the sum of its proper divisors (24997448).

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

21612472 is a wasteful number, since it uses less digits than its factorization.

With its successor (21612473) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (2491).

21612472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2491 (or 2487 counting only the distinct ones).

The product of its digits is 1344, while the sum is 25.

The square root of 21612472 is about 4648.9215953810. The cubic root of 21612472 is about 278.5489214589.

The spelling of 21612472 in words is "twenty-one million, six hundred twelve thousand, four hundred seventy-two".