221539853 has 4 divisors (see below), whose sum is σ = 221571228. Its totient is φ = 221508480.

The previous prime is 221539819. The next prime is 221539859. The reversal of 221539853 is 358935122.

221539853 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 25623844 + 195916009 = 5062^2 + 13997^2 .

It is a cyclic number.

It is not a de Polignac number, because 221539853 - 2¹⁸ = 221277709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221539859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 413 + ... + 21053.

It is an arithmetic number, because the mean of its divisors is an integer number (55392807).

Almost surely, 2^221539853 is an apocalyptic number.

It is an amenable number.

221539853 is a deficient number, since it is larger than the sum of its proper divisors (31375).

221539853 is a wasteful number, since it uses less digits than its factorization.

221539853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31374.

The product of its digits is 64800, while the sum is 38.

The square root of 221539853 is about 14884.2148936382. The cubic root of 221539853 is about 605.0862550335.

The spelling of 221539853 in words is "two hundred twenty-one million, five hundred thirty-nine thousand, eight hundred fifty-three".