221384641 has 3 divisors (see below), whose sum is σ = 221399521. Its totient is φ = 221369762.

The previous prime is 221384633. The next prime is 221384651. The reversal of 221384641 is 146483122.

The square root of 221384641 is 14879.

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

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 is not a de Polignac number, because 221384641 - 2³ = 221384633 is a prime.

It is a super-2 number, since 2×221384641² = 98022318541397762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221384621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7440 + ... + 22318.

Almost surely, 2^221384641 is an apocalyptic number.

221384641 is the 14879-th square number.

221384641 is the 7440-th centered octagonal number.

It is an amenable number.

221384641 is a deficient number, since it is larger than the sum of its proper divisors (14880).

221384641 is an frugal number, since it uses more digits than its factorization.

221384641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29758 (or 14879 counting only the distinct ones).

The product of its digits is 9216, while the sum is 31.

The cubic root of 221384641 is about 604.9449131366.

Multiplying 221384641 by its product of digits (9216), we get a square (2040280851456 = 1428384²).

The spelling of 221384641 in words is "two hundred twenty-one million, three hundred eighty-four thousand, six hundred forty-one".