21111022131 has 4 divisors (see below), whose sum is σ = 28148029512. Its totient is φ = 14074014752.

The previous prime is 21111022117. The next prime is 21111022133. The reversal of 21111022131 is 13122011112.

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 21111022131 - 2⁶ = 21111022067 is a prime.

It is a super-2 number, since 2×21111022131² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21111022131.

It is not an unprimeable number, because it can be changed into a prime (21111022133) 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, 3518503686 + ... + 3518503691.

It is an arithmetic number, because the mean of its divisors is an integer number (7037007378).

Almost surely, 2^21111022131 is an apocalyptic number.

21111022131 is a deficient number, since it is larger than the sum of its proper divisors (7037007381).

21111022131 is an equidigital number, since it uses as much as digits as its factorization.

21111022131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7037007380.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21111022131 its reverse (13122011112), we get a palindrome (34233033243).

The spelling of 21111022131 in words is "twenty-one billion, one hundred eleven million, twenty-two thousand, one hundred thirty-one".