221085645 has 32 divisors (see below), whose sum is σ = 398352384. Its totient is φ = 103732800.

The previous prime is 221085607. The next prime is 221085649. The reversal of 221085645 is 546580122.

It is not a de Polignac number, because 221085645 - 2⁶ = 221085581 is a prime.

It is a super-3 number, since 3×221085645³ (a number of 26 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221085649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16497 + ... + 26726.

It is an arithmetic number, because the mean of its divisors is an integer number (12448512).

Almost surely, 2^221085645 is an apocalyptic number.

It is an amenable number.

221085645 is a deficient number, since it is larger than the sum of its proper divisors (177266739).

221085645 is a wasteful number, since it uses less digits than its factorization.

221085645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43273.

The product of its (nonzero) digits is 19200, while the sum is 33.

The square root of 221085645 is about 14868.9490213666. The cubic root of 221085645 is about 604.6724497920.

The spelling of 221085645 in words is "two hundred twenty-one million, eighty-five thousand, six hundred forty-five".