221709226 has 4 divisors (see below), whose sum is σ = 332563842. Its totient is φ = 110854612.

The previous prime is 221709211. The next prime is 221709239. The reversal of 221709226 is 622907122.

221709226 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, and also an emirpimes, since its reverse is a distinct semiprime: 622907122 = 2 ⋅311453561.

It can be written as a sum of positive squares in only one way, i.e., 118788201 + 102921025 = 10899^2 + 10145^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55427305 + ... + 55427308.

Almost surely, 2^221709226 is an apocalyptic number.

221709226 is a deficient number, since it is larger than the sum of its proper divisors (110854616).

221709226 is a wasteful number, since it uses less digits than its factorization.

221709226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110854615.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 221709226 is about 14889.9034919639. The cubic root of 221709226 is about 605.2404171649.

The spelling of 221709226 in words is "two hundred twenty-one million, seven hundred nine thousand, two hundred twenty-six".