166989799 has 4 divisors (see below), whose sum is σ = 169341840. Its totient is φ = 164637760.

The previous prime is 166989787. The next prime is 166989811. The reversal of 166989799 is 997989661.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (166989787) and next prime (166989811).

It is a cyclic number.

It is not a de Polignac number, because 166989799 - 2⁹ = 166989287 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166989799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166989709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1175914 + ... + 1176055.

It is an arithmetic number, because the mean of its divisors is an integer number (42335460).

Almost surely, 2^166989799 is an apocalyptic number.

166989799 is a deficient number, since it is larger than the sum of its proper divisors (2352041).

166989799 is an equidigital number, since it uses as much as digits as its factorization.

166989799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2352040.

The product of its digits is 13226976, while the sum is 64.

The square root of 166989799 is about 12922.4532887529. The cubic root of 166989799 is about 550.6766317024.

The spelling of 166989799 in words is "one hundred sixty-six million, nine hundred eighty-nine thousand, seven hundred ninety-nine".