111143561 has 2 divisors, whose sum is σ = 111143562. Its totient is φ = 111143560.

The previous prime is 111143533. The next prime is 111143609. The reversal of 111143561 is 165341111.

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., 83905600 + 27237961 = 9160^2 + 5219^2 .

It is a cyclic number.

It is not a de Polignac number, because 111143561 - 2²² = 106949257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (111193561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55571780 + 55571781.

It is an arithmetic number, because the mean of its divisors is an integer number (55571781).

Almost surely, 2^111143561 is an apocalyptic number.

It is an amenable number.

111143561 is a deficient number, since it is larger than the sum of its proper divisors (1).

111143561 is an equidigital number, since it uses as much as digits as its factorization.

111143561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 23.

The square root of 111143561 is about 10542.4646549087. The cubic root of 111143561 is about 480.7966530521.

Adding to 111143561 its reverse (165341111), we get a palindrome (276484672).

The spelling of 111143561 in words is "one hundred eleven million, one hundred forty-three thousand, five hundred sixty-one".