111231961 has 2 divisors, whose sum is σ = 111231962. Its totient is φ = 111231960.

The previous prime is 111231959. The next prime is 111231971. The reversal of 111231961 is 169132111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69822736 + 41409225 = 8356^2 + 6435^2 .

It is an emirp because it is prime and its reverse (169132111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 111231961 - 2¹ = 111231959 is a prime.

Together with 111231959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (111231971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55615980 + 55615981.

It is an arithmetic number, because the mean of its divisors is an integer number (55615981).

Almost surely, 2^111231961 is an apocalyptic number.

It is an amenable number.

111231961 is a deficient number, since it is larger than the sum of its proper divisors (1).

111231961 is an equidigital number, since it uses as much as digits as its factorization.

111231961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 324, while the sum is 25.

The square root of 111231961 is about 10546.6563895862. The cubic root of 111231961 is about 480.9240893168.

The spelling of 111231961 in words is "one hundred eleven million, two hundred thirty-one thousand, nine hundred sixty-one".