189886979 has 4 divisors (see below), whose sum is σ = 189935976. Its totient is φ = 189837984.

The previous prime is 189886973. The next prime is 189886981. The reversal of 189886979 is 979688981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 979688981 = 73 ⋅13420397.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-189886979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189886973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18134 + ... + 26619.

It is an arithmetic number, because the mean of its divisors is an integer number (47483994).

Almost surely, 2^189886979 is an apocalyptic number.

189886979 is a deficient number, since it is larger than the sum of its proper divisors (48997).

189886979 is an equidigital number, since it uses as much as digits as its factorization.

189886979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48996.

The product of its digits is 15676416, while the sum is 65.

The square root of 189886979 is about 13779.9484396713. The cubic root of 189886979 is about 574.7756947414.

The spelling of 189886979 in words is "one hundred eighty-nine million, eight hundred eighty-six thousand, nine hundred seventy-nine".