21221331311 has 2 divisors, whose sum is σ = 21221331312. Its totient is φ = 21221331310.

The previous prime is 21221331269. The next prime is 21221331347. The reversal of 21221331311 is 11313312212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21221331311 - 2³⁰ = 20147589487 is a prime.

It is a super-2 number, since 2×21221331311² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221331011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610665655 + 10610665656.

It is an arithmetic number, because the mean of its divisors is an integer number (10610665656).

Almost surely, 2^21221331311 is an apocalyptic number.

21221331311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221331311 is an equidigital number, since it uses as much as digits as its factorization.

21221331311 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 20.

Adding to 21221331311 its reverse (11313312212), we get a palindrome (32534643523).

The spelling of 21221331311 in words is "twenty-one billion, two hundred twenty-one million, three hundred thirty-one thousand, three hundred eleven".