21310312 has 16 divisors (see below), whose sum is σ = 40011300. Its totient is φ = 10640640.

The previous prime is 21310309. The next prime is 21310319. The reversal of 21310312 is 21301312.

It can be written as a sum of positive squares in 2 ways, for example, as 21288996 + 21316 = 4614^2 + 146^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21310292 and 21310301.

It is not an unprimeable number, because it can be changed into a prime (21310319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6864 + ... + 9472.

Almost surely, 2^21310312 is an apocalyptic number.

It is an amenable number.

21310312 is a deficient number, since it is larger than the sum of its proper divisors (18700988).

21310312 is a wasteful number, since it uses less digits than its factorization.

21310312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3636 (or 3632 counting only the distinct ones).

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

The square root of 21310312 is about 4616.3093483864. The cubic root of 21310312 is about 277.2447107017.

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

The spelling of 21310312 in words is "twenty-one million, three hundred ten thousand, three hundred twelve".