6668727491 has 8 divisors (see below), whose sum is σ = 6844155264. Its totient is φ = 6495136960.

The previous prime is 6668727467. The next prime is 6668727497. The reversal of 6668727491 is 1947278666.

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

It is a cyclic number.

It is not a de Polignac number, because 6668727491 - 2⁶ = 6668727427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6668727497) 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, 451955 + ... + 466476.

It is an arithmetic number, because the mean of its divisors is an integer number (855519408).

Almost surely, 2^6668727491 is an apocalyptic number.

6668727491 is a deficient number, since it is larger than the sum of its proper divisors (175427773).

6668727491 is a wasteful number, since it uses less digits than its factorization.

6668727491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 918621.

The product of its digits is 6096384, while the sum is 56.

The square root of 6668727491 is about 81662.2770378098. The cubic root of 6668727491 is about 1882.2659687773.

The spelling of 6668727491 in words is "six billion, six hundred sixty-eight million, seven hundred twenty-seven thousand, four hundred ninety-one".