3818572221 has 4 divisors (see below), whose sum is σ = 5091429632. Its totient is φ = 2545714812.

The previous prime is 3818572211. The next prime is 3818572231. The reversal of 3818572221 is 1222758183.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (3818572211) and next prime (3818572231).

It is not a de Polignac number, because 3818572221 - 2⁵ = 3818572189 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 3818572221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3818572201) 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 3 ways as a sum of consecutive naturals, for example, 636428701 + ... + 636428706.

It is an arithmetic number, because the mean of its divisors is an integer number (1272857408).

Almost surely, 2^3818572221 is an apocalyptic number.

It is an amenable number.

3818572221 is a deficient number, since it is larger than the sum of its proper divisors (1272857411).

3818572221 is a wasteful number, since it uses less digits than its factorization.

3818572221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1272857410.

The product of its digits is 53760, while the sum is 39.

The square root of 3818572221 is about 61794.5970210989. The cubic root of 3818572221 is about 1563.0288815356.

The spelling of 3818572221 in words is "three billion, eight hundred eighteen million, five hundred seventy-two thousand, two hundred twenty-one".