21002312 has 16 divisors (see below), whose sum is σ = 41091840. Its totient is φ = 10044496.

The previous prime is 21002299. The next prime is 21002323. The reversal of 21002312 is 21320012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21002293 and 21002302.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56888 + ... + 57255.

It is an arithmetic number, because the mean of its divisors is an integer number (2568240).

Almost surely, 2^21002312 is an apocalyptic number.

It is an amenable number.

21002312 is a deficient number, since it is larger than the sum of its proper divisors (20089528).

21002312 is a wasteful number, since it uses less digits than its factorization.

21002312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114172 (or 114168 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21002312 is about 4582.8279478942. The cubic root of 21002312 is about 275.9025420804.

Adding to 21002312 its reverse (21320012), we get a palindrome (42322324).

The spelling of 21002312 in words is "twenty-one million, two thousand, three hundred twelve".