2171998 has 8 divisors (see below), whose sum is σ = 3282192. Its totient is φ = 1077936.

The previous prime is 2171989. The next prime is 2171999. The reversal of 2171998 is 8991712.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2171999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3690 + ... + 4237.

It is an arithmetic number, because the mean of its divisors is an integer number (410274).

2^2171998 is an apocalyptic number.

2171998 is a deficient number, since it is larger than the sum of its proper divisors (1110194).

2171998 is a wasteful number, since it uses less digits than its factorization.

2171998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8066.

The product of its digits is 9072, while the sum is 37.

The square root of 2171998 is about 1473.7699956235. The cubic root of 2171998 is about 129.5049813481.

The spelling of 2171998 in words is "two million, one hundred seventy-one thousand, nine hundred ninety-eight".