642221163789 has 64 divisors (see below), whose sum is σ = 934392775680. Its totient is φ = 390835143680.

The previous prime is 642221163781. The next prime is 642221163791. The reversal of 642221163789 is 987361122246.

It is a cyclic number.

It is not a de Polignac number, because 642221163789 - 2³ = 642221163781 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642221163781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 272472799 + ... + 272475155.

It is an arithmetic number, because the mean of its divisors is an integer number (14599887120).

Almost surely, 2^642221163789 is an apocalyptic number.

It is an amenable number.

642221163789 is a deficient number, since it is larger than the sum of its proper divisors (292171611891).

642221163789 is a wasteful number, since it uses less digits than its factorization.

642221163789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3610.

The product of its digits is 1741824, while the sum is 51.

The spelling of 642221163789 in words is "six hundred forty-two billion, two hundred twenty-one million, one hundred sixty-three thousand, seven hundred eighty-nine".