221006685 has 16 divisors (see below), whose sum is σ = 357114240. Its totient is φ = 116702400.

The previous prime is 221006683. The next prime is 221006707. The reversal of 221006685 is 586600122.

It is not a de Polignac number, because 221006685 - 2¹ = 221006683 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221006683) 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, 71425 + ... + 74454.

It is an arithmetic number, because the mean of its divisors is an integer number (22319640).

Almost surely, 2^221006685 is an apocalyptic number.

It is an amenable number.

221006685 is a deficient number, since it is larger than the sum of its proper divisors (136107555).

221006685 is a wasteful number, since it uses less digits than its factorization.

221006685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145988.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 221006685 is about 14866.2935864996. The cubic root of 221006685 is about 604.6004556383.

The spelling of 221006685 in words is "two hundred twenty-one million, six thousand, six hundred eighty-five".