221161845 has 16 divisors (see below), whose sum is σ = 360536832. Its totient is φ = 115727040.

The previous prime is 221161819. The next prime is 221161849. The reversal of 221161845 is 548161122.

It is not a de Polignac number, because 221161845 - 2¹⁴ = 221145461 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 138301 + ... + 139890.

It is an arithmetic number, because the mean of its divisors is an integer number (22533552).

Almost surely, 2^221161845 is an apocalyptic number.

It is an amenable number.

221161845 is a deficient number, since it is larger than the sum of its proper divisors (139374987).

221161845 is a wasteful number, since it uses less digits than its factorization.

221161845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278252.

The product of its digits is 3840, while the sum is 30.

The square root of 221161845 is about 14871.5111875021. The cubic root of 221161845 is about 604.7419111812.

The spelling of 221161845 in words is "two hundred twenty-one million, one hundred sixty-one thousand, eight hundred forty-five".