19800985 has 8 divisors (see below), whose sum is σ = 23794056. Its totient is φ = 15818880.

The previous prime is 19800961. The next prime is 19801003. The reversal of 19800985 is 58900891.

It can be written as a sum of positive squares in 4 ways, for example, as 4769856 + 15031129 = 2184^2 + 3877^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19800985 - 2¹⁷ = 19669913 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1975 + ... + 6595.

It is an arithmetic number, because the mean of its divisors is an integer number (2974257).

Almost surely, 2^19800985 is an apocalyptic number.

It is an amenable number.

19800985 is a deficient number, since it is larger than the sum of its proper divisors (3993071).

19800985 is an equidigital number, since it uses as much as digits as its factorization.

19800985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5483.

The product of its (nonzero) digits is 25920, while the sum is 40.

The square root of 19800985 is about 4449.8297720250. The cubic root of 19800985 is about 270.5384089516.

The spelling of 19800985 in words is "nineteen million, eight hundred thousand, nine hundred eighty-five".