666783349 has 4 divisors (see below), whose sum is σ = 666858636. Its totient is φ = 666708064.

The previous prime is 666783331. The next prime is 666783373. The reversal of 666783349 is 943387666.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 366454449 + 300328900 = 19143^2 + 17330^2 .

It is a cyclic number.

It is not a de Polignac number, because 666783349 - 2²⁵ = 633228917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666783296 and 666783305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666783149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22264 + ... + 42769.

It is an arithmetic number, because the mean of its divisors is an integer number (166714659).

Almost surely, 2^666783349 is an apocalyptic number.

It is an amenable number.

666783349 is a deficient number, since it is larger than the sum of its proper divisors (75287).

666783349 is a wasteful number, since it uses less digits than its factorization.

666783349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75286.

The product of its digits is 3919104, while the sum is 52.

The square root of 666783349 is about 25822.1484195254. The cubic root of 666783349 is about 873.6314274667.

The spelling of 666783349 in words is "six hundred sixty-six million, seven hundred eighty-three thousand, three hundred forty-nine".