221302145 has 4 divisors (see below), whose sum is σ = 265562580. Its totient is φ = 177041712.

The previous prime is 221302111. The next prime is 221302163. The reversal of 221302145 is 541203122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 541203122 = 2 ⋅270601561.

It can be written as a sum of positive squares in 2 ways, for example, as 138109504 + 83192641 = 11752^2 + 9121^2 .

It is a cyclic number.

It is not a de Polignac number, because 221302145 - 2²⁰ = 220253569 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22130210 + ... + 22130219.

It is an arithmetic number, because the mean of its divisors is an integer number (66390645).

Almost surely, 2^221302145 is an apocalyptic number.

It is an amenable number.

221302145 is a deficient number, since it is larger than the sum of its proper divisors (44260435).

221302145 is an equidigital number, since it uses as much as digits as its factorization.

221302145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44260434.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 221302145 is about 14876.2275123769. The cubic root of 221302145 is about 604.8697622807.

Adding to 221302145 its reverse (541203122), we get a palindrome (762505267).

The spelling of 221302145 in words is "two hundred twenty-one million, three hundred two thousand, one hundred forty-five".