2161999983996 has 18 divisors (see below), whose sum is σ = 5465055515192. Its totient is φ = 720666661320.

The previous prime is 2161999983953. The next prime is 2161999984031. The reversal of 2161999983996 is 6993899991612.

It is a happy number.

2161999983996 is a `hidden beast` number, since 216 + 1 + 9 + 9 + 9 + 9 + 8 + 399 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×2161999983996² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 30027777520 + ... + 30027777591.

Almost surely, 2^{2161999983996} is an apocalyptic number.

It is an amenable number.

2161999983996 is an abundant number, since it is smaller than the sum of its proper divisors (3303055531196).

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

2161999983996 is a wasteful number, since it uses less digits than its factorization.

2161999983996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60055555121 (or 60055555116 counting only the distinct ones).

The product of its digits is 918330048, while the sum is 81.

The spelling of 2161999983996 in words is "two trillion, one hundred sixty-one billion, nine hundred ninety-nine million, nine hundred eighty-three thousand, nine hundred ninety-six".