6641695217 has 4 divisors (see below), whose sum is σ = 6870719220. Its totient is φ = 6412671216.

The previous prime is 6641695183. The next prime is 6641695243. The reversal of 6641695217 is 7125961466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1345349041 + 5296346176 = 36679^2 + 72776^2 .

It is a cyclic number.

It is not a de Polignac number, because 6641695217 - 2¹⁰ = 6641694193 is a prime.

It is a super-2 number, since 2×6641695217² = 88224230711041354178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6641697217) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 114511958 + ... + 114512015.

It is an arithmetic number, because the mean of its divisors is an integer number (1717679805).

Almost surely, 2^6641695217 is an apocalyptic number.

It is an amenable number.

6641695217 is a deficient number, since it is larger than the sum of its proper divisors (229024003).

6641695217 is a wasteful number, since it uses less digits than its factorization.

6641695217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229024002.

The product of its digits is 544320, while the sum is 47.

The square root of 6641695217 is about 81496.5963522404. The cubic root of 6641695217 is about 1879.7192142335.

The spelling of 6641695217 in words is "six billion, six hundred forty-one million, six hundred ninety-five thousand, two hundred seventeen".