221161565 has 8 divisors (see below), whose sum is σ = 265493760. Its totient is φ = 176862672.

The previous prime is 221161553. The next prime is 221161579. The reversal of 221161565 is 565161122.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 221161565 - 2¹⁸ = 220899421 is a prime.

It is a congruent number.

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, 9932 + ... + 23258.

It is an arithmetic number, because the mean of its divisors is an integer number (33186720).

Almost surely, 2^221161565 is an apocalyptic number.

It is an amenable number.

221161565 is a deficient number, since it is larger than the sum of its proper divisors (44332195).

221161565 is a wasteful number, since it uses less digits than its factorization.

221161565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16651.

The product of its digits is 3600, while the sum is 29.

The square root of 221161565 is about 14871.5017735264. The cubic root of 221161565 is about 604.7416559717.

The spelling of 221161565 in words is "two hundred twenty-one million, one hundred sixty-one thousand, five hundred sixty-five".