2015221 has 4 divisors (see below), whose sum is σ = 2170252. Its totient is φ = 1860192.

The previous prime is 2015213. The next prime is 2015267. The reversal of 2015221 is 1225102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 192721 + 1822500 = 439^2 + 1350^2 .

It is a cyclic number.

It is not a de Polignac number, because 2015221 - 2³ = 2015213 is a prime.

It is a super-2 number, since 2×2015221² = 8122231357682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 155017 = 2015221 / (2 + 0 + 1 + 5 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2015201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77496 + ... + 77521.

It is an arithmetic number, because the mean of its divisors is an integer number (542563).

2^2015221 is an apocalyptic number.

It is an amenable number.

2015221 is a deficient number, since it is larger than the sum of its proper divisors (155031).

2015221 is a wasteful number, since it uses less digits than its factorization.

2015221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155030.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 2015221 is about 1419.5847984534. The cubic root of 2015221 is about 126.3109185469.

The spelling of 2015221 in words is "two million, fifteen thousand, two hundred twenty-one".