221502145 has 16 divisors (see below), whose sum is σ = 275418000. Its totient is φ = 170811648.

The previous prime is 221502143. The next prime is 221502173. The reversal of 221502145 is 541205122.

It can be written as a sum of positive squares in 8 ways, for example, as 24127744 + 197374401 = 4912^2 + 14049^2 .

It is a cyclic number.

It is not a de Polignac number, because 221502145 - 2¹ = 221502143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221502143) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 154291 + ... + 155719.

It is an arithmetic number, because the mean of its divisors is an integer number (17213625).

Almost surely, 2^221502145 is an apocalyptic number.

It is an amenable number.

221502145 is a deficient number, since it is larger than the sum of its proper divisors (53915855).

221502145 is a wasteful number, since it uses less digits than its factorization.

221502145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2532.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 221502145 is about 14882.9481286471. The cubic root of 221502145 is about 605.0519227800.

Adding to 221502145 its reverse (541205122), we get a palindrome (762707267).

The spelling of 221502145 in words is "two hundred twenty-one million, five hundred two thousand, one hundred forty-five".