221623643 has 8 divisors (see below), whose sum is σ = 225212400. Its totient is φ = 218063200.

The previous prime is 221623627. The next prime is 221623651. The reversal of 221623643 is 346326122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221623643 - 2⁴ = 221623627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221623663) 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 7 ways as a sum of consecutive naturals, for example, 8993 + ... + 22893.

It is an arithmetic number, because the mean of its divisors is an integer number (28151550).

Almost surely, 2^221623643 is an apocalyptic number.

221623643 is a deficient number, since it is larger than the sum of its proper divisors (3588757).

221623643 is a wasteful number, since it uses less digits than its factorization.

221623643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14157.

The product of its digits is 10368, while the sum is 29.

The square root of 221623643 is about 14887.0293544414. The cubic root of 221623643 is about 605.1625299280.

Adding to 221623643 its reverse (346326122), we get a palindrome (567949765).

The spelling of 221623643 in words is "two hundred twenty-one million, six hundred twenty-three thousand, six hundred forty-three".