111109961 has 2 divisors, whose sum is σ = 111109962. Its totient is φ = 111109960.

The previous prime is 111109949. The next prime is 111109981. The reversal of 111109961 is 169901111.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104448400 + 6661561 = 10220^2 + 2581^2 .

It is a cyclic number.

It is not a de Polignac number, because 111109961 - 2¹⁰ = 111108937 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (111109981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55554980 + 55554981.

It is an arithmetic number, because the mean of its divisors is an integer number (55554981).

Almost surely, 2^111109961 is an apocalyptic number.

It is an amenable number.

111109961 is a deficient number, since it is larger than the sum of its proper divisors (1).

111109961 is an equidigital number, since it uses as much as digits as its factorization.

111109961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 29.

The square root of 111109961 is about 10540.8709791933. The cubic root of 111109961 is about 480.7481980162.

The spelling of 111109961 in words is "one hundred eleven million, one hundred nine thousand, nine hundred sixty-one".