189399979 has 2 divisors, whose sum is σ = 189399980. Its totient is φ = 189399978.

The previous prime is 189399949. The next prime is 189399983. The reversal of 189399979 is 979993981.

It is a strong prime.

It is an emirp because it is prime and its reverse (979993981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 189399979 - 2¹⁷ = 189268907 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 189399979.

It is not a weakly prime, because it can be changed into another prime (189399949) 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, 94699989 + 94699990.

It is an arithmetic number, because the mean of its divisors is an integer number (94699990).

Almost surely, 2^189399979 is an apocalyptic number.

189399979 is a deficient number, since it is larger than the sum of its proper divisors (1).

189399979 is an equidigital number, since it uses as much as digits as its factorization.

189399979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9920232, while the sum is 64.

The square root of 189399979 is about 13762.2664921153. The cubic root of 189399979 is about 574.2839014919.

The spelling of 189399979 in words is "one hundred eighty-nine million, three hundred ninety-nine thousand, nine hundred seventy-nine".