21337312 has 48 divisors (see below), whose sum is σ = 45278352. Its totient is φ = 9861120.

The previous prime is 21337297. The next prime is 21337367. The reversal of 21337312 is 21373312.

It is a happy number.

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, 32863 + ... + 33505.

It is an arithmetic number, because the mean of its divisors is an integer number (943299).

Almost surely, 2^21337312 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 21337312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22639176).

21337312 is an abundant number, since it is smaller than the sum of its proper divisors (23941040).

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

21337312 is a wasteful number, since it uses less digits than its factorization.

21337312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731 (or 723 counting only the distinct ones).

The product of its digits is 756, while the sum is 22.

The square root of 21337312 is about 4619.2328367382. The cubic root of 21337312 is about 277.3617502522.

The spelling of 21337312 in words is "twenty-one million, three hundred thirty-seven thousand, three hundred twelve".