221505985 has 32 divisors (see below), whose sum is σ = 287400960. Its totient is φ = 163468800.

The previous prime is 221505983. The next prime is 221505989. The reversal of 221505985 is 589505122.

It is not a de Polignac number, because 221505985 - 2¹ = 221505983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221505983) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 513720 + ... + 514150.

It is an arithmetic number, because the mean of its divisors is an integer number (8981280).

Almost surely, 2^221505985 is an apocalyptic number.

It is an amenable number.

221505985 is a deficient number, since it is larger than the sum of its proper divisors (65894975).

221505985 is a wasteful number, since it uses less digits than its factorization.

221505985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609.

The product of its (nonzero) digits is 36000, while the sum is 37.

The square root of 221505985 is about 14883.0771347863. The cubic root of 221505985 is about 605.0554191885.

The spelling of 221505985 in words is "two hundred twenty-one million, five hundred five thousand, nine hundred eighty-five".