3998643505 has 8 divisors (see below), whose sum is σ = 4798722600. Its totient is φ = 3198681216.

The previous prime is 3998643503. The next prime is 3998643557. The reversal of 3998643505 is 5053468993.

It can be written as a sum of positive squares in 4 ways, for example, as 1276204176 + 2722439329 = 35724^2 + 52177^2 .

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 3998643505 - 2¹ = 3998643503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3998643503) 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, 91411 + ... + 127879.

It is an arithmetic number, because the mean of its divisors is an integer number (599840325).

Almost surely, 2^3998643505 is an apocalyptic number.

It is an amenable number.

3998643505 is a deficient number, since it is larger than the sum of its proper divisors (800079095).

3998643505 is a wasteful number, since it uses less digits than its factorization.

3998643505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58403.

The product of its (nonzero) digits is 3499200, while the sum is 52.

The square root of 3998643505 is about 63234.8282594331. The cubic root of 3998643505 is about 1587.2215898809.

The spelling of 3998643505 in words is "three billion, nine hundred ninety-eight million, six hundred forty-three thousand, five hundred five".