166986989 has 8 divisors (see below), whose sum is σ = 182296632. Its totient is φ = 152029440.

The previous prime is 166986979. The next prime is 166986997. The reversal of 166986989 is 989689661.

166986989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 49589764 + 117397225 = 7042^2 + 10835^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166986989 is a prime.

It is a super-2 number, since 2×166986989² = 55769308990572242, which contains 22 as substring.

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 (166986979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87032 + ... + 88929.

It is an arithmetic number, because the mean of its divisors is an integer number (22787079).

Almost surely, 2^166986989 is an apocalyptic number.

It is an amenable number.

166986989 is a deficient number, since it is larger than the sum of its proper divisors (15309643).

166986989 is a wasteful number, since it uses less digits than its factorization.

166986989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176047.

The product of its digits is 10077696, while the sum is 62.

The square root of 166986989 is about 12922.3445628106. The cubic root of 166986989 is about 550.6735428710.

The spelling of 166986989 in words is "one hundred sixty-six million, nine hundred eighty-six thousand, nine hundred eighty-nine".