221503689 has 45 divisors (see below), whose sum is σ = 360735895. Its totient is φ = 130970400.

The previous prime is 221503687. The next prime is 221503717. The reversal of 221503689 is 986305122.

The square root of 221503689 is 14883.

It is a perfect power (a square), and thus also a powerful number.

221503689 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 10673289 + 210830400 = 3267^2 + 14520^2 .

It is not a de Polignac number, because 221503689 - 2¹ = 221503687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221503687) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 5402509 + ... + 5402549.

Almost surely, 2^221503689 is an apocalyptic number.

221503689 is the 14883-rd square number.

221503689 is the 7442-nd centered octagonal number.

It is an amenable number.

221503689 is a deficient number, since it is larger than the sum of its proper divisors (139232206).

221503689 is an frugal number, since it uses more digits than its factorization.

221503689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 55 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The cubic root of 221503689 is about 605.0533286325.

Multiplying 221503689 by its sum of digits (36), we get a square (7974132804 = 89298²).

The spelling of 221503689 in words is "two hundred twenty-one million, five hundred three thousand, six hundred eighty-nine".