21301312 has 56 divisors (see below), whose sum is σ = 45720000. Its totient is φ = 9816576.

The previous prime is 21301279. The next prime is 21301321. The reversal of 21301312 is 21310312.

It is a junction number, because it is equal to n+sod(n) for n = 21301292 and 21301301.

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, 42439 + ... + 42937.

Almost surely, 2^21301312 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 21301312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22860000).

21301312 is an abundant number, since it is smaller than the sum of its proper divisors (24418688).

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

21301312 is a wasteful number, since it uses less digits than its factorization.

21301312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563 (or 553 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21301312 is about 4615.3344407529. The cubic root of 21301312 is about 277.2056755507.

Adding to 21301312 its reverse (21310312), we get a palindrome (42611624).

The spelling of 21301312 in words is "twenty-one million, three hundred one thousand, three hundred twelve".