21313121331 has 8 divisors (see below), whose sum is σ = 28641255424. Its totient is φ = 14096867400.

The previous prime is 21313121329. The next prime is 21313121341. The reversal of 21313121331 is 13312131312.

It is a happy number.

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

It is not a de Polignac number, because 21313121331 - 2¹ = 21313121329 is a prime.

It is a super-2 number, since 2×21313121331² (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 = 21313121298 and 21313121307.

It is not an unprimeable number, because it can be changed into a prime (21313121311) 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 7 ways as a sum of consecutive naturals, for example, 27969595 + ... + 27970356.

It is an arithmetic number, because the mean of its divisors is an integer number (3580156928).

Almost surely, 2^21313121331 is an apocalyptic number.

21313121331 is a deficient number, since it is larger than the sum of its proper divisors (7328134093).

21313121331 is a wasteful number, since it uses less digits than its factorization.

21313121331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55940081.

The product of its digits is 324, while the sum is 21.

Adding to 21313121331 its reverse (13312131312), we get a palindrome (34625252643).

The spelling of 21313121331 in words is "twenty-one billion, three hundred thirteen million, one hundred twenty-one thousand, three hundred thirty-one".