21533612 has 48 divisors (see below), whose sum is σ = 42147840. Its totient is φ = 9580032.

The previous prime is 21533597. The next prime is 21533647. The reversal of 21533612 is 21633512.

It is a Harshad number since it is a multiple of its sum of digits (23).

Its product of digits (1080) is a multiple of the sum of its prime factors (270).

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, 169493 + ... + 169619.

It is an arithmetic number, because the mean of its divisors is an integer number (878080).

Almost surely, 2^21533612 is an apocalyptic number.

It is an amenable number.

21533612 is a deficient number, since it is larger than the sum of its proper divisors (20614228).

21533612 is a wasteful number, since it uses less digits than its factorization.

21533612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270 (or 268 counting only the distinct ones).

The product of its digits is 1080, while the sum is 23.

The square root of 21533612 is about 4640.4323074472. The cubic root of 21533612 is about 278.2097170196.

The spelling of 21533612 in words is "twenty-one million, five hundred thirty-three thousand, six hundred twelve".