21427312 has 10 divisors (see below), whose sum is σ = 41515448. Its totient is φ = 10713648.

The previous prime is 21427309. The next prime is 21427319. The reversal of 21427312 is 21372412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21427319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 669588 + ... + 669619.

Almost surely, 2^21427312 is an apocalyptic number.

It is an amenable number.

21427312 is a deficient number, since it is larger than the sum of its proper divisors (20088136).

21427312 is a wasteful number, since it uses less digits than its factorization.

21427312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1339215 (or 1339209 counting only the distinct ones).

The product of its digits is 672, while the sum is 22.

The square root of 21427312 is about 4628.9644630306. The cubic root of 21427312 is about 277.7511704767.

Adding to 21427312 its reverse (21372412), we get a palindrome (42799724).

The spelling of 21427312 in words is "twenty-one million, four hundred twenty-seven thousand, three hundred twelve".