221845145 has 16 divisors (see below), whose sum is σ = 275847168. Its totient is φ = 171097920.

The previous prime is 221845073. The next prime is 221845147. The reversal of 221845145 is 541548122.

221845145 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221845145 - 2¹⁰ = 221844121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221845147) 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, 40352 + ... + 45518.

It is an arithmetic number, because the mean of its divisors is an integer number (17240448).

Almost surely, 2^221845145 is an apocalyptic number.

It is an amenable number.

221845145 is a deficient number, since it is larger than the sum of its proper divisors (54002023).

221845145 is a wasteful number, since it uses less digits than its factorization.

221845145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5480.

The product of its digits is 12800, while the sum is 32.

The square root of 221845145 is about 14894.4669256741. The cubic root of 221845145 is about 605.3640729232.

The spelling of 221845145 in words is "two hundred twenty-one million, eight hundred forty-five thousand, one hundred forty-five".