221991235 has 8 divisors (see below), whose sum is σ = 266885136. Its totient is φ = 177262560.

The previous prime is 221991221. The next prime is 221991247. The reversal of 221991235 is 532199122.

221991235 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 221991235 - 2¹⁵ = 221958467 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221991235.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38329 + ... + 43738.

It is an arithmetic number, because the mean of its divisors is an integer number (33360642).

Almost surely, 2^221991235 is an apocalyptic number.

221991235 is a deficient number, since it is larger than the sum of its proper divisors (44893901).

221991235 is an equidigital number, since it uses as much as digits as its factorization.

221991235 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82613.

The product of its digits is 9720, while the sum is 34.

The square root of 221991235 is about 14899.3702887068. The cubic root of 221991235 is about 605.4969257018.

The spelling of 221991235 in words is "two hundred twenty-one million, nine hundred ninety-one thousand, two hundred thirty-five".