171986990 has 32 divisors (see below), whose sum is σ = 359092224. Its totient is φ = 58085280.

The previous prime is 171986987. The next prime is 171987001. The reversal of 171986990 is 99689171.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13646 + ... + 23025.

It is an arithmetic number, because the mean of its divisors is an integer number (11221632).

Almost surely, 2^171986990 is an apocalyptic number.

171986990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

171986990 is an abundant number, since it is smaller than the sum of its proper divisors (187105234).

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

171986990 is a wasteful number, since it uses less digits than its factorization.

171986990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36752.

The product of its (nonzero) digits is 244944, while the sum is 50.

The square root of 171986990 is about 13114.3810376243. The cubic root of 171986990 is about 556.1157544994.

The spelling of 171986990 in words is "one hundred seventy-one million, nine hundred eighty-six thousand, nine hundred ninety".