21302312 has 8 divisors (see below), whose sum is σ = 39941850. Its totient is φ = 10651152.

The previous prime is 21302299. The next prime is 21302321. The reversal of 21302312 is 21320312.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15319396 + 5982916 = 3914^2 + 2446^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1331387 + ... + 1331402.

Almost surely, 2^21302312 is an apocalyptic number.

It is an amenable number.

21302312 is a deficient number, since it is larger than the sum of its proper divisors (18639538).

21302312 is a wasteful number, since it uses less digits than its factorization.

21302312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2662795 (or 2662791 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21302312 is about 4615.4427739925. The cubic root of 21302312 is about 277.2100133326.

Adding to 21302312 its reverse (21320312), we get a palindrome (42622624).

The spelling of 21302312 in words is "twenty-one million, three hundred two thousand, three hundred twelve".