166618890 has 32 divisors (see below), whose sum is σ = 444317760. Its totient is φ = 44431632.

The previous prime is 166618889. The next prime is 166618897. The reversal of 166618890 is 98816661.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (166618897) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 308284 + ... + 308823.

It is an arithmetic number, because the mean of its divisors is an integer number (13884930).

Almost surely, 2^166618890 is an apocalyptic number.

166618890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

166618890 is an abundant number, since it is smaller than the sum of its proper divisors (277698870).

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

166618890 is a wasteful number, since it uses less digits than its factorization.

166618890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617123 (or 617117 counting only the distinct ones).

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

The square root of 166618890 is about 12908.0939723880. The cubic root of 166618890 is about 550.2686180978.

The spelling of 166618890 in words is "one hundred sixty-six million, six hundred eighteen thousand, eight hundred ninety".