6664691 has 8 divisors (see below), whose sum is σ = 7379904. Its totient is φ = 5967720.

The previous prime is 6664667. The next prime is 6664711. The reversal of 6664691 is 1964666.

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

It is not a de Polignac number, because 6664691 - 2¹⁴ = 6648307 is a prime.

It is a super-2 number, since 2×6664691² = 88836212250962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6664631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3785 + ... + 5258.

It is an arithmetic number, because the mean of its divisors is an integer number (922488).

Almost surely, 2^6664691 is an apocalyptic number.

6664691 is a deficient number, since it is larger than the sum of its proper divisors (715213).

6664691 is a wasteful number, since it uses less digits than its factorization.

6664691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9121.

The product of its digits is 46656, while the sum is 38.

The square root of 6664691 is about 2581.6062829177. The cubic root of 6664691 is about 188.1886122042.

The spelling of 6664691 in words is "six million, six hundred sixty-four thousand, six hundred ninety-one".