221906473 has 4 divisors (see below), whose sum is σ = 227318868. Its totient is φ = 216494080.

The previous prime is 221906449. The next prime is 221906483. The reversal of 221906473 is 374609122.

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 39980329 + 181926144 = 6323^2 + 13488^2 .

It is a cyclic number.

It is not a de Polignac number, because 221906473 - 2⁵ = 221906441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221906483) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2706136 + ... + 2706217.

It is an arithmetic number, because the mean of its divisors is an integer number (56829717).

Almost surely, 2^221906473 is an apocalyptic number.

It is an amenable number.

221906473 is a deficient number, since it is larger than the sum of its proper divisors (5412395).

221906473 is an equidigital number, since it uses as much as digits as its factorization.

221906473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5412394.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 221906473 is about 14896.5255344996. The cubic root of 221906473 is about 605.4198510912.

The spelling of 221906473 in words is "two hundred twenty-one million, nine hundred six thousand, four hundred seventy-three".