2117887805 has 18 divisors (see below), whose sum is σ = 2795005374. Its totient is φ = 1539458800.

The previous prime is 2117887741. The next prime is 2117887819. The reversal of 2117887805 is 5087887112.

It can be written as a sum of positive squares in only one way, i.e., 1694310244 + 423577561 = 41162^2 + 20581^2 .

It is not a de Polignac number, because 2117887805 - 2⁶ = 2117887741 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2117887805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1131020 + ... + 1132890.

Almost surely, 2^2117887805 is an apocalyptic number.

It is an amenable number.

2117887805 is a deficient number, since it is larger than the sum of its proper divisors (677117569).

2117887805 is an frugal number, since it uses more digits than its factorization.

2117887805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3769 (or 1887 counting only the distinct ones).

The product of its (nonzero) digits is 250880, while the sum is 47.

The square root of 2117887805 is about 46020.5150449232. The cubic root of 2117887805 is about 1284.2048818952.

Multiplying 2117887805 by its product of nonzero digits (250880), we get a square (531335692518400 = 23050720²).

The spelling of 2117887805 in words is "two billion, one hundred seventeen million, eight hundred eighty-seven thousand, eight hundred five".