642828866 has 8 divisors (see below), whose sum is σ = 964925184. Its totient is φ = 321187140.

The previous prime is 642828859. The next prime is 642828869. The reversal of 642828866 is 668828246.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (642828869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110090 + ... + 115781.

It is an arithmetic number, because the mean of its divisors is an integer number (120615648).

Almost surely, 2^642828866 is an apocalyptic number.

642828866 is a deficient number, since it is larger than the sum of its proper divisors (322096318).

642828866 is a wasteful number, since it uses less digits than its factorization.

642828866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227296.

The product of its digits is 1769472, while the sum is 50.

The square root of 642828866 is about 25354.0700085805. The cubic root of 642828866 is about 863.0417196445.

The spelling of 642828866 in words is "six hundred forty-two million, eight hundred twenty-eight thousand, eight hundred sixty-six".