2161998 has 16 divisors (see below), whose sum is σ = 4804560. Its totient is φ = 720648.

The previous prime is 2161987. The next prime is 2162003. The reversal of 2161998 is 8991612.

It is a Curzon number.

It is a congruent 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, 19965 + ... + 20072.

It is an arithmetic number, because the mean of its divisors is an integer number (300285).

2^2161998 is an apocalyptic number.

2161998 is an abundant number, since it is smaller than the sum of its proper divisors (2642562).

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

2161998 is a wasteful number, since it uses less digits than its factorization.

2161998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40048 (or 40042 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 2161998 is about 1470.3734219578. The cubic root of 2161998 is about 129.3059261607.

The spelling of 2161998 in words is "two million, one hundred sixty-one thousand, nine hundred ninety-eight".