6665749 has 4 divisors (see below), whose sum is σ = 6708364. Its totient is φ = 6623136.

The previous prime is 6665741. The next prime is 6665773. The reversal of 6665749 is 9475666.

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 4284900 + 2380849 = 2070^2 + 1543^2 .

It is a cyclic number.

It is not a de Polignac number, because 6665749 - 2³ = 6665741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6665741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21072 + ... + 21385.

It is an arithmetic number, because the mean of its divisors is an integer number (1677091).

Almost surely, 2^6665749 is an apocalyptic number.

It is an amenable number.

6665749 is a deficient number, since it is larger than the sum of its proper divisors (42615).

6665749 is a wasteful number, since it uses less digits than its factorization.

6665749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42614.

The product of its digits is 272160, while the sum is 43.

The square root of 6665749 is about 2581.8111859700. The cubic root of 6665749 is about 188.1985698060.

The spelling of 6665749 in words is "six million, six hundred sixty-five thousand, seven hundred forty-nine".