2915221 has 4 divisors (see below), whose sum is σ = 2918700. Its totient is φ = 2911744.

The previous prime is 2915219. The next prime is 2915243. The reversal of 2915221 is 1225192.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 192721 + 2722500 = 439^2 + 1650^2 .

It is a cyclic number.

It is not a de Polignac number, because 2915221 - 2¹ = 2915219 is a prime.

It is a Duffinian number.

2915221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2915192 and 2915201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2915201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 375 + ... + 2443.

It is an arithmetic number, because the mean of its divisors is an integer number (729675).

2^2915221 is an apocalyptic number.

It is an amenable number.

2915221 is a deficient number, since it is larger than the sum of its proper divisors (3479).

2915221 is a wasteful number, since it uses less digits than its factorization.

2915221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3478.

The product of its digits is 360, while the sum is 22.

The square root of 2915221 is about 1707.4018273388. The cubic root of 2915221 is about 142.8533714719.

It can be divided in two parts, 2915 and 221, that added together give a square (3136 = 56²).

The spelling of 2915221 in words is "two million, nine hundred fifteen thousand, two hundred twenty-one".