642215384855 has 32 divisors (see below), whose sum is σ = 844657968960. Its totient is φ = 464878356480.

The previous prime is 642215384849. The next prime is 642215384893. The reversal of 642215384855 is 558483512246.

It is a de Polignac number, because none of the positive numbers 2^k-642215384855 is a prime.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 642215384797 and 642215384806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53812469 + ... + 53824401.

It is an arithmetic number, because the mean of its divisors is an integer number (26395561530).

Almost surely, 2^642215384855 is an apocalyptic number.

642215384855 is a deficient number, since it is larger than the sum of its proper divisors (202442584105).

642215384855 is a wasteful number, since it uses less digits than its factorization.

642215384855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16451.

The product of its digits is 9216000, while the sum is 53.

The spelling of 642215384855 in words is "six hundred forty-two billion, two hundred fifteen million, three hundred eighty-four thousand, eight hundred fifty-five".