188117009 has 2 divisors, whose sum is σ = 188117010. Its totient is φ = 188117008.

The previous prime is 188116987. The next prime is 188117057. The reversal of 188117009 is 900711881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131446225 + 56670784 = 11465^2 + 7528^2 .

It is an emirp because it is prime and its reverse (900711881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 188117009 - 2¹² = 188112913 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 188117009.

It is not a weakly prime, because it can be changed into another prime (188114009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94058504 + 94058505.

It is an arithmetic number, because the mean of its divisors is an integer number (94058505).

Almost surely, 2^188117009 is an apocalyptic number.

It is an amenable number.

188117009 is a deficient number, since it is larger than the sum of its proper divisors (1).

188117009 is an equidigital number, since it uses as much as digits as its factorization.

188117009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 188117009 is about 13715.5754162922. The cubic root of 188117009 is about 572.9842551971.

The spelling of 188117009 in words is "one hundred eighty-eight million, one hundred seventeen thousand, nine".