221346645 has 16 divisors (see below), whose sum is σ = 381397632. Its totient is φ = 108970560.

The previous prime is 221346623. The next prime is 221346661. The reversal of 221346645 is 546643122.

It is not a de Polignac number, because 221346645 - 2¹¹ = 221344597 is a prime.

It is a Curzon number.

It is a congruent 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, 567361 + ... + 567750.

It is an arithmetic number, because the mean of its divisors is an integer number (23837352).

Almost surely, 2^221346645 is an apocalyptic number.

It is an amenable number.

221346645 is a deficient number, since it is larger than the sum of its proper divisors (160050987).

221346645 is a wasteful number, since it uses less digits than its factorization.

221346645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1135132.

The product of its digits is 34560, while the sum is 33.

The square root of 221346645 is about 14877.7231120894. The cubic root of 221346645 is about 604.9103024820.

Adding to 221346645 its reverse (546643122), we get a palindrome (767989767).

The spelling of 221346645 in words is "two hundred twenty-one million, three hundred forty-six thousand, six hundred forty-five".