2106500665 has 8 divisors (see below), whose sum is σ = 2589454728. Its totient is φ = 1644097920.

The previous prime is 2106500657. The next prime is 2106500677. The reversal of 2106500665 is 5660056012.

It can be written as a sum of positive squares in 4 ways, for example, as 57942544 + 2048558121 = 7612^2 + 45261^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2106500665 - 2³ = 2106500657 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5137602 + ... + 5138011.

It is an arithmetic number, because the mean of its divisors is an integer number (323681841).

Almost surely, 2^2106500665 is an apocalyptic number.

It is an amenable number.

2106500665 is a deficient number, since it is larger than the sum of its proper divisors (482954063).

2106500665 is a wasteful number, since it uses less digits than its factorization.

2106500665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10275659.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 2106500665 is about 45896.6302139928. The cubic root of 2106500665 is about 1281.8991715162.

Adding to 2106500665 its reverse (5660056012), we get a palindrome (7766556677).

The spelling of 2106500665 in words is "two billion, one hundred six million, five hundred thousand, six hundred sixty-five".