21413312 has 56 divisors (see below), whose sum is σ = 45061632. Its totient is φ = 10080000.

The previous prime is 21413303. The next prime is 21413369. The reversal of 21413312 is 21331412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85187 + ... + 85437.

It is an arithmetic number, because the mean of its divisors is an integer number (804672).

Almost surely, 2^21413312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21413312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22530816).

21413312 is an abundant number, since it is smaller than the sum of its proper divisors (23648320).

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

21413312 is a wasteful number, since it uses less digits than its factorization.

21413312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337 (or 327 counting only the distinct ones).

The product of its digits is 144, while the sum is 17.

The square root of 21413312 is about 4627.4519986705. The cubic root of 21413312 is about 277.6906657094.

Adding to 21413312 its reverse (21331412), we get a palindrome (42744724).

The spelling of 21413312 in words is "twenty-one million, four hundred thirteen thousand, three hundred twelve".