21000202312 has 16 divisors (see below), whose sum is σ = 39426329340. Its totient is φ = 10486514496.

The previous prime is 21000202309. The next prime is 21000202319. The reversal of 21000202312 is 21320200012.

It can be written as a sum of positive squares in 2 ways, for example, as 15623500036 + 5376702276 = 124994^2 + 73326^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21000202292 and 21000202301.

It is not an unprimeable number, because it can be changed into a prime (21000202319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1691763 + ... + 1704130.

Almost surely, 2^21000202312 is an apocalyptic number.

It is an amenable number.

21000202312 is a deficient number, since it is larger than the sum of its proper divisors (18426127028).

21000202312 is a wasteful number, since it uses less digits than its factorization.

21000202312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3396672 (or 3396668 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

Adding to 21000202312 its reverse (21320200012), we get a palindrome (42320402324).

The spelling of 21000202312 in words is "twenty-one billion, two hundred two thousand, three hundred twelve".