221011985 has 16 divisors (see below), whose sum is σ = 284207616. Its totient is φ = 164398848.

The previous prime is 221011943. The next prime is 221011993. The reversal of 221011985 is 589110122.

It is a cyclic number.

It is not a de Polignac number, because 221011985 - 2¹² = 221007889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8609 + ... + 22718.

It is an arithmetic number, because the mean of its divisors is an integer number (17762976).

Almost surely, 2^221011985 is an apocalyptic number.

It is an amenable number.

221011985 is a deficient number, since it is larger than the sum of its proper divisors (63195631).

221011985 is a wasteful number, since it uses less digits than its factorization.

221011985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31432.

The product of its (nonzero) digits is 1440, while the sum is 29.

The square root of 221011985 is about 14866.4718410254. The cubic root of 221011985 is about 604.6052886094.

The spelling of 221011985 in words is "two hundred twenty-one million, eleven thousand, nine hundred eighty-five".