21412644 has 36 divisors (see below), whose sum is σ = 54921552. Its totient is φ = 6488240.

The previous prime is 21412631. The next prime is 21412649. The reversal of 21412644 is 44621412.

It is a happy number.

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 (21412649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5922 + ... + 8825.

Almost surely, 2^21412644 is an apocalyptic number.

It is an amenable number.

21412644 is an abundant number, since it is smaller than the sum of its proper divisors (33508908).

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

21412644 is a wasteful number, since it uses less digits than its factorization.

21412644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14776 (or 14763 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

The square root of 21412644 is about 4627.3798201574. The cubic root of 21412644 is about 277.6877781085.

The spelling of 21412644 in words is "twenty-one million, four hundred twelve thousand, six hundred forty-four".