221228261 has 8 divisors (see below), whose sum is σ = 224601984. Its totient is φ = 217861840.

The previous prime is 221228257. The next prime is 221228297. The reversal of 221228261 is 162822122.

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

It is a cyclic number.

It is not a de Polignac number, because 221228261 - 2² = 221228257 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 221228261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221228221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104960 + ... + 107046.

It is an arithmetic number, because the mean of its divisors is an integer number (28075248).

Almost surely, 2^221228261 is an apocalyptic number.

It is an amenable number.

221228261 is a deficient number, since it is larger than the sum of its proper divisors (3373723).

221228261 is a wasteful number, since it uses less digits than its factorization.

221228261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3651.

The product of its digits is 1536, while the sum is 26.

The square root of 221228261 is about 14873.7440142017. The cubic root of 221228261 is about 604.8024407886.

The spelling of 221228261 in words is "two hundred twenty-one million, two hundred twenty-eight thousand, two hundred sixty-one".