21000331213 has 4 divisors (see below), whose sum is σ = 21002261920. Its totient is φ = 20998400508.

The previous prime is 21000331199. The next prime is 21000331259. The reversal of 21000331213 is 31213300012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000331213 is a prime.

It is a super-2 number, since 2×21000331213² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000331613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 948945 + ... + 970822.

It is an arithmetic number, because the mean of its divisors is an integer number (5250565480).

Almost surely, 2^21000331213 is an apocalyptic number.

It is an amenable number.

21000331213 is a deficient number, since it is larger than the sum of its proper divisors (1930707).

21000331213 is a wasteful number, since it uses less digits than its factorization.

21000331213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1930706.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21000331213 its reverse (31213300012), we get a palindrome (52213631225).

The spelling of 21000331213 in words is "twenty-one billion, three hundred thirty-one thousand, two hundred thirteen".