221155284 has 24 divisors (see below), whose sum is σ = 589747648. Its totient is φ = 63187200.

The previous prime is 221155237. The next prime is 221155289. The reversal of 221155284 is 482551122.

It is a super-2 number, since 2×221155284² = 97819319282241312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221155289) 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, 1316317 + ... + 1316484.

Almost surely, 2^221155284 is an apocalyptic number.

It is an amenable number.

221155284 is an abundant number, since it is smaller than the sum of its proper divisors (368592364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221155284 is a wasteful number, since it uses less digits than its factorization.

221155284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2632815 (or 2632813 counting only the distinct ones).

The product of its digits is 6400, while the sum is 30.

The square root of 221155284 is about 14871.2905963134. The cubic root of 221155284 is about 604.7359310193.

The spelling of 221155284 in words is "two hundred twenty-one million, one hundred fifty-five thousand, two hundred eighty-four".