21210304331 has 4 divisors (see below), whose sum is σ = 21211412472. Its totient is φ = 21209196192.

The previous prime is 21210304321. The next prime is 21210304343. The reversal of 21210304331 is 13340301212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21210304331 - 2⁶ = 21210304267 is a prime.

It is a super-2 number, since 2×21210304331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210304321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 524846 + ... + 563811.

It is an arithmetic number, because the mean of its divisors is an integer number (5302853118).

Almost surely, 2^21210304331 is an apocalyptic number.

21210304331 is a deficient number, since it is larger than the sum of its proper divisors (1108141).

21210304331 is a wasteful number, since it uses less digits than its factorization.

21210304331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1108140.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21210304331 its reverse (13340301212), we get a palindrome (34550605543).

The spelling of 21210304331 in words is "twenty-one billion, two hundred ten million, three hundred four thousand, three hundred thirty-one".