21331312331 has 8 divisors (see below), whose sum is σ = 25661729280. Its totient is φ = 17321667048.

The previous prime is 21331312279. The next prime is 21331312339. The reversal of 21331312331 is 13321313312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21331312331 - 2¹⁰ = 21331311307 is a prime.

It is a super-2 number, since 2×21331312331² (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 = 21331312297 and 21331312306.

It is not an unprimeable number, because it can be changed into a prime (21331312339) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80192771 + ... + 80193036.

It is an arithmetic number, because the mean of its divisors is an integer number (3207716160).

Almost surely, 2^21331312331 is an apocalyptic number.

21331312331 is a deficient number, since it is larger than the sum of its proper divisors (4330416949).

21331312331 is a wasteful number, since it uses less digits than its factorization.

21331312331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160385833.

The product of its digits is 972, while the sum is 23.

Adding to 21331312331 its reverse (13321313312), we get a palindrome (34652625643).

The spelling of 21331312331 in words is "twenty-one billion, three hundred thirty-one million, three hundred twelve thousand, three hundred thirty-one".