1998813185 has 16 divisors (see below), whose sum is σ = 2414373456. Its totient is φ = 1588543488.

The previous prime is 1998813127. The next prime is 1998813191. The reversal of 1998813185 is 5813188991.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 7921 + 1998805264 = 89^2 + 44708^2 .

It is a cyclic number.

It is not a de Polignac number, because 1998813185 - 2⁶ = 1998813121 is a prime.

It is a Duffinian 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, 1250807 + ... + 1252403.

It is an arithmetic number, because the mean of its divisors is an integer number (150898341).

Almost surely, 2^1998813185 is an apocalyptic number.

It is an amenable number.

1998813185 is a deficient number, since it is larger than the sum of its proper divisors (415560271).

1998813185 is a wasteful number, since it uses less digits than its factorization.

1998813185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3092.

The product of its digits is 622080, while the sum is 53.

The square root of 1998813185 is about 44708.0885858476. The cubic root of 1998813185 is about 1259.6717850497.

The spelling of 1998813185 in words is "one billion, nine hundred ninety-eight million, eight hundred thirteen thousand, one hundred eighty-five".