2161723898 has 8 divisors (see below), whose sum is σ = 3413248320. Its totient is φ = 1023974460.

The previous prime is 2161723873. The next prime is 2161723901. The reversal of 2161723898 is 8983271612.

It is a happy number.

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

It is a super-2 number, since 2×2161723898² = 9346100422368628808, which contains 22 as substring.

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, 28443698 + ... + 28443773.

It is an arithmetic number, because the mean of its divisors is an integer number (426656040).

Almost surely, 2^2161723898 is an apocalyptic number.

2161723898 is a deficient number, since it is larger than the sum of its proper divisors (1251524422).

2161723898 is a wasteful number, since it uses less digits than its factorization.

2161723898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56887492.

The product of its digits is 290304, while the sum is 47.

The square root of 2161723898 is about 46494.3426451004. The cubic root of 2161723898 is about 1293.0046138372.

The spelling of 2161723898 in words is "two billion, one hundred sixty-one million, seven hundred twenty-three thousand, eight hundred ninety-eight".