166681980 has 72 divisors (see below), whose sum is σ = 507579072. Its totient is φ = 44274816.

The previous prime is 166681973. The next prime is 166682023. The reversal of 166681980 is 89186661.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48189 + ... + 51531.

Almost surely, 2^166681980 is an apocalyptic number.

166681980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166681980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253789536).

166681980 is an abundant number, since it is smaller than the sum of its proper divisors (340897092).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166681980 is a wasteful number, since it uses less digits than its factorization.

166681980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3635 (or 3630 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 166681980 is about 12910.5375565853. The cubic root of 166681980 is about 550.3380621371.

The spelling of 166681980 in words is "one hundred sixty-six million, six hundred eighty-one thousand, nine hundred eighty".