3918808321 has 4 divisors (see below), whose sum is σ = 3919439700. Its totient is φ = 3918176944.

The previous prime is 3918808319. The next prime is 3918808357. The reversal of 3918808321 is 1238088193.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1238088193 = 41 ⋅30197273.

It can be written as a sum of positive squares in 2 ways, for example, as 580279921 + 3338528400 = 24089^2 + 57780^2 .

It is a cyclic number.

It is not a de Polignac number, because 3918808321 - 2¹ = 3918808319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3918808381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 306286 + ... + 318823.

It is an arithmetic number, because the mean of its divisors is an integer number (979859925).

Almost surely, 2^3918808321 is an apocalyptic number.

It is an amenable number.

3918808321 is a deficient number, since it is larger than the sum of its proper divisors (631379).

3918808321 is an equidigital number, since it uses as much as digits as its factorization.

3918808321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631378.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 3918808321 is about 62600.3859492895. The cubic root of 3918808321 is about 1576.5872395290.

The spelling of 3918808321 in words is "three billion, nine hundred eighteen million, eight hundred eight thousand, three hundred twenty-one".