666946091 has 8 divisors (see below), whose sum is σ = 807060960. Its totient is φ = 538040448.

The previous prime is 666946081. The next prime is 666946103. The reversal of 666946091 is 190649666.

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 666946091 - 2¹⁴ = 666929707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666946081) 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, 2802176 + ... + 2802413.

It is an arithmetic number, because the mean of its divisors is an integer number (100882620).

Almost surely, 2^666946091 is an apocalyptic number.

666946091 is a deficient number, since it is larger than the sum of its proper divisors (140114869).

666946091 is a wasteful number, since it uses less digits than its factorization.

666946091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5604613.

The product of its (nonzero) digits is 419904, while the sum is 47.

The square root of 666946091 is about 25825.2994367926. The cubic root of 666946091 is about 873.7024975079.

The spelling of 666946091 in words is "six hundred sixty-six million, nine hundred forty-six thousand, ninety-one".