205445320013221 has 4 divisors (see below), whose sum is σ = 205452912535200. Its totient is φ = 205437727491244.

The previous prime is 205445320013203. The next prime is 205445320013309. The reversal of 205445320013221 is 122310023544502.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205445320013221 is a prime.

It is a super-2 number, since 2×205445320013221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205445320013621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3796220401 + ... + 3796274518.

It is an arithmetic number, because the mean of its divisors is an integer number (51363228133800).

Almost surely, 2^{205445320013221} is an apocalyptic number.

It is an amenable number.

205445320013221 is a deficient number, since it is larger than the sum of its proper divisors (7592521979).

205445320013221 is an equidigital number, since it uses as much as digits as its factorization.

205445320013221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7592521978.

The product of its (nonzero) digits is 57600, while the sum is 34.

Adding to 205445320013221 its reverse (122310023544502), we get a palindrome (327755343557723).

The spelling of 205445320013221 in words is "two hundred five trillion, four hundred forty-five billion, three hundred twenty million, thirteen thousand, two hundred twenty-one".