21112221311 has 2 divisors, whose sum is σ = 21112221312. Its totient is φ = 21112221310.

The previous prime is 21112221287. The next prime is 21112221323. The reversal of 21112221311 is 11312221112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112221311 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21112221311.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112221371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556110655 + 10556110656.

It is an arithmetic number, because the mean of its divisors is an integer number (10556110656).

Almost surely, 2^21112221311 is an apocalyptic number.

21112221311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112221311 is an equidigital number, since it uses as much as digits as its factorization.

21112221311 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48, while the sum is 17.

Adding to 21112221311 its reverse (11312221112), we get a palindrome (32424442423).

The spelling of 21112221311 in words is "twenty-one billion, one hundred twelve million, two hundred twenty-one thousand, three hundred eleven".