2173771987 has 16 divisors (see below), whose sum is σ = 2287872000. Its totient is φ = 2062609920.

The previous prime is 2173771967. The next prime is 2173772047. The reversal of 2173771987 is 7891773712.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2173771987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2173771927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 819898 + ... + 822544.

It is an arithmetic number, because the mean of its divisors is an integer number (142992000).

Almost surely, 2^2173771987 is an apocalyptic number.

2173771987 is a deficient number, since it is larger than the sum of its proper divisors (114100013).

2173771987 is a wasteful number, since it uses less digits than its factorization.

2173771987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3186.

The product of its digits is 1037232, while the sum is 52.

The square root of 2173771987 is about 46623.7277252688. The cubic root of 2173771987 is about 1295.4022963636.

The spelling of 2173771987 in words is "two billion, one hundred seventy-three million, seven hundred seventy-one thousand, nine hundred eighty-seven".