642067784165 has 8 divisors (see below), whose sum is σ = 770497774200. Its totient is φ = 513643271872.

The previous prime is 642067784143. The next prime is 642067784173. The reversal of 642067784165 is 561487760246.

It can be written as a sum of positive squares in 4 ways, for example, as 13864120516 + 628203663649 = 117746^2 + 792593^2 .

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 642067784165 - 2⁸ = 642067783909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642067784165.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1106990 + ... + 1584159.

It is an arithmetic number, because the mean of its divisors is an integer number (96312221775).

Almost surely, 2^642067784165 is an apocalyptic number.

It is an amenable number.

642067784165 is a deficient number, since it is larger than the sum of its proper divisors (128429990035).

642067784165 is a wasteful number, since it uses less digits than its factorization.

642067784165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2738871.

The product of its (nonzero) digits is 13547520, while the sum is 56.

The spelling of 642067784165 in words is "six hundred forty-two billion, sixty-seven million, seven hundred eighty-four thousand, one hundred sixty-five".