642256433006563 has 4 divisors (see below), whose sum is σ = 642381215687640. Its totient is φ = 642131650325488.

The previous prime is 642256433006509. The next prime is 642256433006597. The reversal of 642256433006563 is 365600334652246.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642256433006563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642256433006863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62391332818 + ... + 62391343111.

It is an arithmetic number, because the mean of its divisors is an integer number (160595303921910).

Almost surely, 2^{642256433006563} is an apocalyptic number.

642256433006563 is a deficient number, since it is larger than the sum of its proper divisors (124782681077).

642256433006563 is a wasteful number, since it uses less digits than its factorization.

642256433006563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124782681076.

The product of its (nonzero) digits is 55987200, while the sum is 55.

The spelling of 642256433006563 in words is "six hundred forty-two trillion, two hundred fifty-six billion, four hundred thirty-three million, six thousand, five hundred sixty-three".