221388 has 24 divisors (see below), whose sum is σ = 544320. Its totient is φ = 69840.

The previous prime is 221327. The next prime is 221393. The reversal of 221388 is 883122.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 221388.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 258 + ... + 713.

It is an arithmetic number, because the mean of its divisors is an integer number (22680).

2²²¹³⁸⁸ is an apocalyptic number.

It is an amenable number.

221388 is an abundant number, since it is smaller than the sum of its proper divisors (322932).

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

221388 is a wasteful number, since it uses less digits than its factorization.

221388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997 (or 995 counting only the distinct ones).

The product of its digits is 768, while the sum is 24.

The square root of 221388 is about 470.5188625337. The cubic root of 221388 is about 60.4947972668.

The spelling of 221388 in words is "two hundred twenty-one thousand, three hundred eighty-eight".