21164412 has 12 divisors (see below), whose sum is σ = 49383656. Its totient is φ = 7054800.

The previous prime is 21164401. The next prime is 21164431. The reversal of 21164412 is 21446112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

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

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 3 ways as a sum of consecutive naturals, for example, 881839 + ... + 881862.

Almost surely, 2^21164412 is an apocalyptic number.

It is an amenable number.

21164412 is an abundant number, since it is smaller than the sum of its proper divisors (28219244).

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

21164412 is a wasteful number, since it uses less digits than its factorization.

21164412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1763708 (or 1763706 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 21164412 is about 4600.4795402219. The cubic root of 21164412 is about 276.6105471568.

The spelling of 21164412 in words is "twenty-one million, one hundred sixty-four thousand, four hundred twelve".