221643265 has 8 divisors (see below), whose sum is σ = 279970560. Its totient is φ = 167982192.

The previous prime is 221643221. The next prime is 221643271. The reversal of 221643265 is 562346122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221643265 - 2¹⁹ = 221118977 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1166449 + ... + 1166638.

It is an arithmetic number, because the mean of its divisors is an integer number (34996320).

Almost surely, 2^221643265 is an apocalyptic number.

It is an amenable number.

221643265 is a deficient number, since it is larger than the sum of its proper divisors (58327295).

221643265 is a wasteful number, since it uses less digits than its factorization.

221643265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333111.

The product of its digits is 17280, while the sum is 31.

The square root of 221643265 is about 14887.6883699250. The cubic root of 221643265 is about 605.1803892571.

Adding to 221643265 its reverse (562346122), we get a palindrome (783989387).

The spelling of 221643265 in words is "two hundred twenty-one million, six hundred forty-three thousand, two hundred sixty-five".