21996612 has 36 divisors (see below), whose sum is σ = 60658416. Its totient is φ = 6665520.

The previous prime is 21996599. The next prime is 21996613. The reversal of 21996612 is 21669912.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21996613) 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 11 ways as a sum of consecutive naturals, for example, 27378 + ... + 28169.

It is an arithmetic number, because the mean of its divisors is an integer number (1684956).

Almost surely, 2^21996612 is an apocalyptic number.

21996612 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21996612 is an abundant number, since it is smaller than the sum of its proper divisors (38661804).

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

21996612 is a wasteful number, since it uses less digits than its factorization.

21996612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55568 (or 55563 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 21996612 is about 4690.0545839041. The cubic root of 21996612 is about 280.1895485252.

The spelling of 21996612 in words is "twenty-one million, nine hundred ninety-six thousand, six hundred twelve".