2175139665 has 48 divisors (see below), whose sum is σ = 3975079680. Its totient is φ = 1097245440.

The previous prime is 2175139643. The next prime is 2175139679. The reversal of 2175139665 is 5669315712.

It is not a de Polignac number, because 2175139665 - 2⁵ = 2175139633 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2175139665.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 648984 + ... + 652326.

It is an arithmetic number, because the mean of its divisors is an integer number (82814160).

Almost surely, 2^2175139665 is an apocalyptic number.

It is an amenable number.

2175139665 is a deficient number, since it is larger than the sum of its proper divisors (1799940015).

2175139665 is a wasteful number, since it uses less digits than its factorization.

2175139665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4134 (or 4131 counting only the distinct ones).

The product of its digits is 340200, while the sum is 45.

The square root of 2175139665 is about 46638.3926073787. The cubic root of 2175139665 is about 1295.6739166616.

It can be divided in two parts, 21751 and 39665, that added together give a palindrome (61416).

The spelling of 2175139665 in words is "two billion, one hundred seventy-five million, one hundred thirty-nine thousand, six hundred sixty-five".