21221112131 has 2 divisors, whose sum is σ = 21221112132. Its totient is φ = 21221112130.

The previous prime is 21221112091. The next prime is 21221112163. The reversal of 21221112131 is 13121112212.

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-21221112131 is a prime.

It is a super-2 number, since 2×21221112131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21221112431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610556065 + 10610556066.

It is an arithmetic number, because the mean of its divisors is an integer number (10610556066).

Almost surely, 2^21221112131 is an apocalyptic number.

21221112131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221112131 is an equidigital number, since it uses as much as digits as its factorization.

21221112131 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 21221112131 its reverse (13121112212), we get a palindrome (34342224343).

The spelling of 21221112131 in words is "twenty-one billion, two hundred twenty-one million, one hundred twelve thousand, one hundred thirty-one".