21231031111131 has 4 divisors (see below), whose sum is σ = 28308041481512. Its totient is φ = 14154020740752.

The previous prime is 21231031111127. The next prime is 21231031111151. The reversal of 21231031111131 is 13111113013212.

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

It is not a de Polignac number, because 21231031111131 - 2² = 21231031111127 is a prime.

It is a super-2 number, since 2×21231031111131² (a number of 27 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 = 21231031111098 and 21231031111107.

It is not an unprimeable number, because it can be changed into a prime (21231031111151) 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, 3538505185186 + ... + 3538505185191.

It is an arithmetic number, because the mean of its divisors is an integer number (7077010370378).

Almost surely, 2^{21231031111131} is an apocalyptic number.

21231031111131 is a deficient number, since it is larger than the sum of its proper divisors (7077010370381).

21231031111131 is an equidigital number, since it uses as much as digits as its factorization.

21231031111131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7077010370380.

The product of its (nonzero) digits is 108, while the sum is 21.

Adding to 21231031111131 its reverse (13111113013212), we get a palindrome (34342144124343).

The spelling of 21231031111131 in words is "twenty-one trillion, two hundred thirty-one billion, thirty-one million, one hundred eleven thousand, one hundred thirty-one".