221906885 has 4 divisors (see below), whose sum is σ = 266288268. Its totient is φ = 177525504.

The previous prime is 221906863. The next prime is 221906911. The reversal of 221906885 is 588609122.

221906885 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43256929 + 178649956 = 6577^2 + 13366^2 .

It is a cyclic number.

It is not a de Polignac number, because 221906885 - 2¹² = 221902789 is a prime.

It is a super-2 number, since 2×221906885² = 98485331220806450, which contains 22 as substring.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 22190684 + ... + 22190693.

It is an arithmetic number, because the mean of its divisors is an integer number (66572067).

Almost surely, 2^221906885 is an apocalyptic number.

It is an amenable number.

221906885 is a deficient number, since it is larger than the sum of its proper divisors (44381383).

221906885 is an equidigital number, since it uses as much as digits as its factorization.

221906885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44381382.

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 221906885 is about 14896.5393632212. The cubic root of 221906885 is about 605.4202257728.

The spelling of 221906885 in words is "two hundred twenty-one million, nine hundred six thousand, eight hundred eighty-five".