111221111531 has 2 divisors, whose sum is σ = 111221111532. Its totient is φ = 111221111530.

The previous prime is 111221111527. The next prime is 111221111539. The reversal of 111221111531 is 135111122111.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 111221111531 - 2² = 111221111527 is a prime.

It is a super-2 number, since 2×111221111531² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (111221111539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55610555765 + 55610555766.

It is an arithmetic number, because the mean of its divisors is an integer number (55610555766).

Almost surely, 2^111221111531 is an apocalyptic number.

111221111531 is a deficient number, since it is larger than the sum of its proper divisors (1).

111221111531 is an equidigital number, since it uses as much as digits as its factorization.

111221111531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60, while the sum is 20.

Adding to 111221111531 its reverse (135111122111), we get a palindrome (246332233642).

The spelling of 111221111531 in words is "one hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, five hundred thirty-one".