221361523653 has 4 divisors (see below), whose sum is σ = 295148698208. Its totient is φ = 147574349100.

The previous prime is 221361523651. The next prime is 221361523693. The reversal of 221361523653 is 356325163122.

221361523653 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 Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 221361523653 - 2¹ = 221361523651 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 (221361523651) 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 3 ways as a sum of consecutive naturals, for example, 36893587273 + ... + 36893587278.

It is an arithmetic number, because the mean of its divisors is an integer number (73787174552).

Almost surely, 2^221361523653 is an apocalyptic number.

It is an amenable number.

221361523653 is a deficient number, since it is larger than the sum of its proper divisors (73787174555).

221361523653 is an equidigital number, since it uses as much as digits as its factorization.

221361523653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73787174554.

The product of its digits is 194400, while the sum is 39.

Adding to 221361523653 its reverse (356325163122), we get a palindrome (577686686775).

The spelling of 221361523653 in words is "two hundred twenty-one billion, three hundred sixty-one million, five hundred twenty-three thousand, six hundred fifty-three".