221287384565 has 8 divisors (see below), whose sum is σ = 285971389368. Its totient is φ = 163412222400.

The previous prime is 221287384529. The next prime is 221287384567. The reversal of 221287384565 is 565483782122.

It is a happy number.

221287384565 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 4 ways, for example, as 29115620689 + 192171763876 = 170633^2 + 438374^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-221287384565 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 (221287384567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1702210586 + ... + 1702210715.

It is an arithmetic number, because the mean of its divisors is an integer number (35746423671).

Almost surely, 2^221287384565 is an apocalyptic number.

It is an amenable number.

221287384565 is a deficient number, since it is larger than the sum of its proper divisors (64684004803).

221287384565 is a wasteful number, since it uses less digits than its factorization.

221287384565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3404421319.

The product of its digits is 6451200, while the sum is 53.

The spelling of 221287384565 in words is "two hundred twenty-one billion, two hundred eighty-seven million, three hundred eighty-four thousand, five hundred sixty-five".