221560865 has 8 divisors (see below), whose sum is σ = 267015528. Its totient is φ = 176487040.

The previous prime is 221560861. The next prime is 221560873. The reversal of 221560865 is 568065122.

It can be written as a sum of positive squares in 4 ways, for example, as 12845056 + 208715809 = 3584^2 + 14447^2 .

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

It is not a de Polignac number, because 221560865 - 2² = 221560861 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221560861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93926 + ... + 96255.

It is an arithmetic number, because the mean of its divisors is an integer number (33376941).

Almost surely, 2^221560865 is an apocalyptic number.

It is an amenable number.

221560865 is a deficient number, since it is larger than the sum of its proper divisors (45454663).

221560865 is a wasteful number, since it uses less digits than its factorization.

221560865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190419.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 221560865 is about 14884.9207253515. The cubic root of 221560865 is about 605.1053842786.

The spelling of 221560865 in words is "two hundred twenty-one million, five hundred sixty thousand, eight hundred sixty-five".