166764989 has 4 divisors (see below), whose sum is σ = 166791324. Its totient is φ = 166738656.

The previous prime is 166764979. The next prime is 166764991. The reversal of 166764989 is 989467661.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 72965764 + 93799225 = 8542^2 + 9685^2 .

It is a cyclic number.

It is not a de Polignac number, because 166764989 - 2²⁰ = 165716413 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166764979) 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, 2729 + ... + 18465.

It is an arithmetic number, because the mean of its divisors is an integer number (41697831).

Almost surely, 2^166764989 is an apocalyptic number.

It is an amenable number.

166764989 is a deficient number, since it is larger than the sum of its proper divisors (26335).

166764989 is a wasteful number, since it uses less digits than its factorization.

166764989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26334.

The product of its digits is 3919104, while the sum is 56.

The square root of 166764989 is about 12913.7519335010. The cubic root of 166764989 is about 550.4294046062.

The spelling of 166764989 in words is "one hundred sixty-six million, seven hundred sixty-four thousand, nine hundred eighty-nine".