2161999983997 has 24 divisors (see below), whose sum is σ = 2533619564280. Its totient is φ = 1839411141120.

The previous prime is 2161999983953. The next prime is 2161999984031. The reversal of 2161999983997 is 7993899991612.

It can be written as a sum of positive squares in 4 ways, for example, as 1244103775236 + 917896208761 = 1115394^2 + 958069^2 .

It is not a de Polignac number, because 2161999983997 - 2¹⁵ = 2161999951229 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2161999983997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161999983937) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 116723097 + ... + 116741617.

It is an arithmetic number, because the mean of its divisors is an integer number (105567481845).

Almost surely, 2^{2161999983997} is an apocalyptic number.

It is an amenable number.

2161999983997 is a deficient number, since it is larger than the sum of its proper divisors (371619580283).

2161999983997 is a wasteful number, since it uses less digits than its factorization.

2161999983997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36061 (or 36054 counting only the distinct ones).

The product of its digits is 1071385056, while the sum is 82.

The spelling of 2161999983997 in words is "two trillion, one hundred sixty-one billion, nine hundred ninety-nine million, nine hundred eighty-three thousand, nine hundred ninety-seven".