17800985 has 4 divisors (see below), whose sum is σ = 21361188. Its totient is φ = 14240784.

The previous prime is 17800973. The next prime is 17800999. The reversal of 17800985 is 58900871.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58900871 = 5039 ⋅11689.

It can be written as a sum of positive squares in 2 ways, for example, as 6538249 + 11262736 = 2557^2 + 3356^2 .

It is a cyclic number.

It is not a de Polignac number, because 17800985 - 2⁸ = 17800729 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1780094 + ... + 1780103.

It is an arithmetic number, because the mean of its divisors is an integer number (5340297).

Almost surely, 2^17800985 is an apocalyptic number.

It is an amenable number.

17800985 is a deficient number, since it is larger than the sum of its proper divisors (3560203).

17800985 is an equidigital number, since it uses as much as digits as its factorization.

17800985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3560202.

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 17800985 is about 4219.1213540262. The cubic root of 17800985 is about 261.1046932011.

The spelling of 17800985 in words is "seventeen million, eight hundred thousand, nine hundred eighty-five".