641957666 has 8 divisors (see below), whose sum is σ = 1100498880. Its totient is φ = 275124708.

The previous prime is 641957653. The next prime is 641957671. The reversal of 641957666 is 666759146.

641957666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22927046 + ... + 22927073.

It is an arithmetic number, because the mean of its divisors is an integer number (137562360).

Almost surely, 2^641957666 is an apocalyptic number.

641957666 is a deficient number, since it is larger than the sum of its proper divisors (458541214).

641957666 is a wasteful number, since it uses less digits than its factorization.

641957666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45854128.

The product of its digits is 1632960, while the sum is 50.

The square root of 641957666 is about 25336.8835100136. The cubic root of 641957666 is about 862.6516615191.

The spelling of 641957666 in words is "six hundred forty-one million, nine hundred fifty-seven thousand, six hundred sixty-six".