221668735 has 4 divisors (see below), whose sum is σ = 266002488. Its totient is φ = 177334984.

The previous prime is 221668703. The next prime is 221668747. The reversal of 221668735 is 537866122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 537866122 = 2 ⋅268933061.

It is a cyclic number.

It is not a de Polignac number, because 221668735 - 2⁵ = 221668703 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22166869 + ... + 22166878.

It is an arithmetic number, because the mean of its divisors is an integer number (66500622).

Almost surely, 2^221668735 is an apocalyptic number.

221668735 is a deficient number, since it is larger than the sum of its proper divisors (44333753).

221668735 is an equidigital number, since it uses as much as digits as its factorization.

221668735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44333752.

The product of its digits is 120960, while the sum is 40.

The square root of 221668735 is about 14888.5437501456. The cubic root of 221668735 is about 605.2035696804.

The spelling of 221668735 in words is "two hundred twenty-one million, six hundred sixty-eight thousand, seven hundred thirty-five".