3721577221 has 6 divisors (see below), whose sum is σ = 3854333522. Its totient is φ = 3593246160.

The previous prime is 3721577203. The next prime is 3721577227. The reversal of 3721577221 is 1227751273.

3721577221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 1545354721 + 2176222500 = 39311^2 + 46650^2 .

It is not a de Polignac number, because 3721577221 - 2¹¹ = 3721575173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3721577227) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2211750 + ... + 2213431.

Almost surely, 2^3721577221 is an apocalyptic number.

It is an amenable number.

3721577221 is a deficient number, since it is larger than the sum of its proper divisors (132756301).

3721577221 is an equidigital number, since it uses as much as digits as its factorization.

3721577221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4425239 (or 4425210 counting only the distinct ones).

The product of its digits is 41160, while the sum is 37.

The square root of 3721577221 is about 61004.7311361996. The cubic root of 3721577221 is about 1549.6811305211.

The spelling of 3721577221 in words is "three billion, seven hundred twenty-one million, five hundred seventy-seven thousand, two hundred twenty-one".