642866558 has 8 divisors (see below), whose sum is σ = 1015052520. Its totient is φ = 304515720.

The previous prime is 642866557. The next prime is 642866573. The reversal of 642866558 is 855668246.

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

It is a super-2 number, since 2×642866558² = 826554822789534728, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642866557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8458733 + ... + 8458808.

It is an arithmetic number, because the mean of its divisors is an integer number (126881565).

Almost surely, 2^642866558 is an apocalyptic number.

642866558 is a deficient number, since it is larger than the sum of its proper divisors (372185962).

642866558 is a wasteful number, since it uses less digits than its factorization.

642866558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16917562.

The product of its digits is 2764800, while the sum is 50.

The square root of 642866558 is about 25354.8133102967. The cubic root of 642866558 is about 863.0585873441.

The spelling of 642866558 in words is "six hundred forty-two million, eight hundred sixty-six thousand, five hundred fifty-eight".