21312201331 has 4 divisors (see below), whose sum is σ = 21312682672. Its totient is φ = 21311719992.

The previous prime is 21312201329. The next prime is 21312201397. The reversal of 21312201331 is 13310221312.

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 21312201331 - 2¹ = 21312201329 is a prime.

It is a super-2 number, since 2×21312201331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21312201299 and 21312201308.

It is not an unprimeable number, because it can be changed into a prime (21312201931) 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, 166671 + ... + 265336.

It is an arithmetic number, because the mean of its divisors is an integer number (5328170668).

Almost surely, 2^21312201331 is an apocalyptic number.

21312201331 is a deficient number, since it is larger than the sum of its proper divisors (481341).

21312201331 is an equidigital number, since it uses as much as digits as its factorization.

21312201331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481340.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21312201331 its reverse (13310221312), we get a palindrome (34622422643).

The spelling of 21312201331 in words is "twenty-one billion, three hundred twelve million, two hundred one thousand, three hundred thirty-one".