21131252233111 has 4 divisors (see below), whose sum is σ = 21131281880032. Its totient is φ = 21131222586192.

The previous prime is 21131252233099. The next prime is 21131252233127. The reversal of 21131252233111 is 11133225213112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21131252233111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21131252233111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131252233141) 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 3 ways as a sum of consecutive naturals, for example, 13727295 + ... + 15188848.

It is an arithmetic number, because the mean of its divisors is an integer number (5282820470008).

Almost surely, 2^{21131252233111} is an apocalyptic number.

21131252233111 is a deficient number, since it is larger than the sum of its proper divisors (29646921).

21131252233111 is an equidigital number, since it uses as much as digits as its factorization.

21131252233111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29646920.

The product of its digits is 2160, while the sum is 28.

Adding to 21131252233111 its reverse (11133225213112), we get a palindrome (32264477446223).

The spelling of 21131252233111 in words is "twenty-one trillion, one hundred thirty-one billion, two hundred fifty-two million, two hundred thirty-three thousand, one hundred eleven".