21111202231 has 4 divisors (see below), whose sum is σ = 24127088272. Its totient is φ = 18095316192.

The previous prime is 21111202219. The next prime is 21111202291. The reversal of 21111202231 is 13220211112.

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 21111202231 - 2²³ = 21102813623 is a prime.

It is a super-2 number, since 2×21111202231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111202291) 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, 1507943010 + ... + 1507943023.

It is an arithmetic number, because the mean of its divisors is an integer number (6031772068).

Almost surely, 2^21111202231 is an apocalyptic number.

21111202231 is a deficient number, since it is larger than the sum of its proper divisors (3015886041).

21111202231 is an equidigital number, since it uses as much as digits as its factorization.

21111202231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3015886040.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21111202231 its reverse (13220211112), we get a palindrome (34331413343).

The spelling of 21111202231 in words is "twenty-one billion, one hundred eleven million, two hundred two thousand, two hundred thirty-one".