4155515221 has 12 divisors (see below), whose sum is σ = 4918990636. Its totient is φ = 3487144320.

The previous prime is 4155515201. The next prime is 4155515233. The reversal of 4155515221 is 1225155514.

4155515221 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 2 ways, for example, as 789891025 + 3365624196 = 28105^2 + 58014^2 .

It is not a de Polignac number, because 4155515221 - 2²⁷ = 4021297493 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 (4155515201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1319316 + ... + 1322461.

Almost surely, 2^4155515221 is an apocalyptic number.

It is an amenable number.

4155515221 is a deficient number, since it is larger than the sum of its proper divisors (763475415).

4155515221 is a wasteful number, since it uses less digits than its factorization.

4155515221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2641812 (or 2641801 counting only the distinct ones).

The product of its digits is 10000, while the sum is 31.

The square root of 4155515221 is about 64463.2858377542. The cubic root of 4155515221 is about 1607.7121447726.

The spelling of 4155515221 in words is "four billion, one hundred fifty-five million, five hundred fifteen thousand, two hundred twenty-one".