642818855 has 8 divisors (see below), whose sum is σ = 881580192. Its totient is φ = 440790048.

The previous prime is 642818831. The next prime is 642818863. The reversal of 642818855 is 558818246.

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 642818855 - 2⁶ = 642818791 is a prime.

It is a super-2 number, since 2×642818855² = 826432160687022050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9183092 + ... + 9183161.

It is an arithmetic number, because the mean of its divisors is an integer number (110197524).

Almost surely, 2^642818855 is an apocalyptic number.

642818855 is a deficient number, since it is larger than the sum of its proper divisors (238761337).

642818855 is a wasteful number, since it uses less digits than its factorization.

642818855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18366265.

The product of its digits is 614400, while the sum is 47.

The square root of 642818855 is about 25353.8725838875. The cubic root of 642818855 is about 863.0372394705.

The spelling of 642818855 in words is "six hundred forty-two million, eight hundred eighteen thousand, eight hundred fifty-five".