21211121312331 has 4 divisors (see below), whose sum is σ = 28281495083112. Its totient is φ = 14140747541552.

The previous prime is 21211121312317. The next prime is 21211121312363. The reversal of 21211121312331 is 13321312111212.

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 21211121312331 - 2¹⁷ = 21211121181259 is a prime.

It is a super-2 number, since 2×21211121312331² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21211121312431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3535186885386 + ... + 3535186885391.

It is an arithmetic number, because the mean of its divisors is an integer number (7070373770778).

Almost surely, 2^{21211121312331} is an apocalyptic number.

21211121312331 is a deficient number, since it is larger than the sum of its proper divisors (7070373770781).

21211121312331 is an equidigital number, since it uses as much as digits as its factorization.

21211121312331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7070373770780.

The product of its digits is 432, while the sum is 24.

Adding to 21211121312331 its reverse (13321312111212), we get a palindrome (34532433423543).

The spelling of 21211121312331 in words is "twenty-one trillion, two hundred eleven billion, one hundred twenty-one million, three hundred twelve thousand, three hundred thirty-one".