221809863 has 16 divisors (see below), whose sum is σ = 341611776. Its totient is φ = 126522240.

The previous prime is 221809859. The next prime is 221809883. The reversal of 221809863 is 368908122.

It is a happy number.

221809863 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221809863 - 2² = 221809859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221809813) 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, 197131 + ... + 198252.

It is an arithmetic number, because the mean of its divisors is an integer number (21350736).

Almost surely, 2^221809863 is an apocalyptic number.

221809863 is a deficient number, since it is larger than the sum of its proper divisors (119801913).

221809863 is a wasteful number, since it uses less digits than its factorization.

221809863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395414.

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 221809863 is about 14893.2824790239. The cubic root of 221809863 is about 605.3319790835.

The spelling of 221809863 in words is "two hundred twenty-one million, eight hundred nine thousand, eight hundred sixty-three".