221545564236647 has 12 divisors (see below), whose sum is σ = 257559106348176. Its totient is φ = 186677618270880.

The previous prime is 221545564236613. The next prime is 221545564236683. The reversal of 221545564236647 is 746632465545122.

It is a happy number.

It is not a de Polignac number, because 221545564236647 - 2¹⁶ = 221545564171111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221545564236647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221545564236847) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4545992054 + ... + 4546040787.

It is an arithmetic number, because the mean of its divisors is an integer number (21463258862348).

Almost surely, 2^{221545564236647} is an apocalyptic number.

221545564236647 is a deficient number, since it is larger than the sum of its proper divisors (36013542111529).

221545564236647 is an frugal number, since it uses more digits than its factorization.

221545564236647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9092032966 (or 9092032907 counting only the distinct ones).

The product of its digits is 290304000, while the sum is 62.

The spelling of 221545564236647 in words is "two hundred twenty-one trillion, five hundred forty-five billion, five hundred sixty-four million, two hundred thirty-six thousand, six hundred forty-seven".