999972170 has 16 divisors (see below), whose sum is σ = 1800311400. Its totient is φ = 399908544.

The previous prime is 999972167. The next prime is 999972187. The reversal of 999972170 is 71279999.

It can be written as a sum of positive squares in 4 ways, for example, as 698914969 + 301057201 = 26437^2 + 17351^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85856 + ... + 96804.

Almost surely, 2^999972170 is an apocalyptic number.

999972170 is a deficient number, since it is larger than the sum of its proper divisors (800339230).

999972170 is a wasteful number, since it uses less digits than its factorization.

999972170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20089.

The product of its (nonzero) digits is 642978, while the sum is 53.

The square root of 999972170 is about 31622.3365676858. The cubic root of 999972170 is about 999.9907232473.

The spelling of 999972170 in words is "nine hundred ninety-nine million, nine hundred seventy-two thousand, one hundred seventy".