638426645841 has 8 divisors (see below), whose sum is σ = 852112190304. Its totient is φ = 425179432640.

The previous prime is 638426645839. The next prime is 638426645891. The reversal of 638426645841 is 148546624836.

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 638426645841 - 2¹ = 638426645839 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (638426645891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109579416 + ... + 109585241.

It is an arithmetic number, because the mean of its divisors is an integer number (106514023788).

Almost surely, 2^638426645841 is an apocalyptic number.

It is an amenable number.

638426645841 is a deficient number, since it is larger than the sum of its proper divisors (213685544463).

638426645841 is a wasteful number, since it uses less digits than its factorization.

638426645841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219165631.

The product of its digits is 26542080, while the sum is 57.

The spelling of 638426645841 in words is "six hundred thirty-eight billion, four hundred twenty-six million, six hundred forty-five thousand, eight hundred forty-one".