221855623 has 16 divisors (see below), whose sum is σ = 251200512. Its totient is φ = 194112000.

The previous prime is 221855603. The next prime is 221855629. The reversal of 221855623 is 326558122.

It is a cyclic number.

It is not a de Polignac number, because 221855623 - 2⁵ = 221855591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221855629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64128 + ... + 67498.

It is an arithmetic number, because the mean of its divisors is an integer number (15700032).

Almost surely, 2^221855623 is an apocalyptic number.

221855623 is a deficient number, since it is larger than the sum of its proper divisors (29344889).

221855623 is a wasteful number, since it uses less digits than its factorization.

221855623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3606.

The product of its digits is 28800, while the sum is 34.

The square root of 221855623 is about 14894.8186628774. The cubic root of 221855623 is about 605.3736034524.

It can be divided in two parts, 2 and 21855623, that added together give a square (21855625 = 4675²).

The spelling of 221855623 in words is "two hundred twenty-one million, eight hundred fifty-five thousand, six hundred twenty-three".