641666327 has 4 divisors (see below), whose sum is σ = 643342080. Its totient is φ = 639990576.

The previous prime is 641666317. The next prime is 641666353. The reversal of 641666327 is 723666146.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 641666327 - 2¹⁰ = 641665303 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 (641666317) 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, 837302 + ... + 838067.

It is an arithmetic number, because the mean of its divisors is an integer number (160835520).

Almost surely, 2^641666327 is an apocalyptic number.

641666327 is a deficient number, since it is larger than the sum of its proper divisors (1675753).

641666327 is a wasteful number, since it uses less digits than its factorization.

641666327 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1675752.

The product of its digits is 217728, while the sum is 41.

The square root of 641666327 is about 25331.1335514224. The cubic root of 641666327 is about 862.5211429950.

The spelling of 641666327 in words is "six hundred forty-one million, six hundred sixty-six thousand, three hundred twenty-seven".