221800845 has 64 divisors (see below), whose sum is σ = 437944320. Its totient is φ = 93612288.

The previous prime is 221800841. The next prime is 221800861. The reversal of 221800845 is 548008122.

221800845 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221800845 - 2² = 221800841 is a prime.

It is a super-2 number, since 2×221800845² = 98391229685428050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221800841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 68452 + ... + 71618.

It is an arithmetic number, because the mean of its divisors is an integer number (6842880).

Almost surely, 2^221800845 is an apocalyptic number.

It is an amenable number.

221800845 is a deficient number, since it is larger than the sum of its proper divisors (216143475).

221800845 is a wasteful number, since it uses less digits than its factorization.

221800845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3234.

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 221800845 is about 14892.9797220032. The cubic root of 221800845 is about 605.3237754240.

Adding to 221800845 its reverse (548008122), we get a palindrome (769808967).

The spelling of 221800845 in words is "two hundred twenty-one million, eight hundred thousand, eight hundred forty-five".