111721109 has 2 divisors, whose sum is σ = 111721110. Its totient is φ = 111721108.

The previous prime is 111721081. The next prime is 111721133. The reversal of 111721109 is 901127111.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111302500 + 418609 = 10550^2 + 647^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111721109 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111721139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55860554 + 55860555.

It is an arithmetic number, because the mean of its divisors is an integer number (55860555).

Almost surely, 2^111721109 is an apocalyptic number.

It is an amenable number.

111721109 is a deficient number, since it is larger than the sum of its proper divisors (1).

111721109 is an equidigital number, since it uses as much as digits as its factorization.

111721109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126, while the sum is 23.

The square root of 111721109 is about 10569.8206701911. The cubic root of 111721109 is about 481.6280208827.

The spelling of 111721109 in words is "one hundred eleven million, seven hundred twenty-one thousand, one hundred nine".