21111331311231 has 16 divisors (see below), whose sum is σ = 32252346048000. Its totient is φ = 12032606016288.

The previous prime is 21111331311197. The next prime is 21111331311233. The reversal of 21111331311231 is 13211313311112.

It is not a de Polignac number, because 21111331311231 - 2³⁴ = 21094151442047 is a prime.

It is a super-2 number, since 2×21111331311231² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111331311233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1292153131 + ... + 1292169468.

It is an arithmetic number, because the mean of its divisors is an integer number (2015771628000).

Almost surely, 2^{21111331311231} is an apocalyptic number.

21111331311231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21111331311231 is a deficient number, since it is larger than the sum of its proper divisors (11141014736769).

21111331311231 is a wasteful number, since it uses less digits than its factorization.

21111331311231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2584322998.

The product of its digits is 324, while the sum is 24.

Adding to 21111331311231 its reverse (13211313311112), we get a palindrome (34322644622343).

The spelling of 21111331311231 in words is "twenty-one trillion, one hundred eleven billion, three hundred thirty-one million, three hundred eleven thousand, two hundred thirty-one".