221161844 has 24 divisors (see below), whose sum is σ = 395115336. Its totient is φ = 108288000.

The previous prime is 221161819. The next prime is 221161849. The reversal of 221161844 is 448161122.

It can be written as a sum of positive squares in 4 ways, for example, as 8352100 + 212809744 = 2890^2 + 14588^2 .

It is a super-2 number, since 2×221161844² = 97825122482960672, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221161849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56924 + ... + 60684.

It is an arithmetic number, because the mean of its divisors is an integer number (16463139).

Almost surely, 2^221161844 is an apocalyptic number.

It is an amenable number.

221161844 is a deficient number, since it is larger than the sum of its proper divisors (173953492).

221161844 is a wasteful number, since it uses less digits than its factorization.

221161844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4067 (or 4065 counting only the distinct ones).

The product of its digits is 3072, while the sum is 29.

The square root of 221161844 is about 14871.5111538808. The cubic root of 221161844 is about 604.7419102698.

The spelling of 221161844 in words is "two hundred twenty-one million, one hundred sixty-one thousand, eight hundred forty-four".