6666649 has 4 divisors (see below), whose sum is σ = 7272720. Its totient is φ = 6060580.

The previous prime is 6666617. The next prime is 6666679. The reversal of 6666649 is 9466666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6666649 - 2⁵ = 6666617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6666679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 303019 + ... + 303040.

It is an arithmetic number, because the mean of its divisors is an integer number (1818180).

Almost surely, 2^6666649 is an apocalyptic number.

It is an amenable number.

6666649 is a deficient number, since it is larger than the sum of its proper divisors (606071).

6666649 is a wasteful number, since it uses less digits than its factorization.

6666649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606070.

The product of its digits is 279936, while the sum is 43.

The square root of 6666649 is about 2581.9854763341. The cubic root of 6666649 is about 188.2070395264.

It can be divided in two parts, 6666 and 649, that multiplied together give a palindrome (4326234).

The spelling of 6666649 in words is "six million, six hundred sixty-six thousand, six hundred forty-nine".