221355270828169 has 3 divisors (see below), whose sum is σ = 221355285706183. Its totient is φ = 221355255950156.

The previous prime is 221355270828163. The next prime is 221355270828179. The reversal of 221355270828169 is 961828072553122.

The square root of 221355270828169 is 14878013.

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 can be written as a sum of positive squares in only one way, i.e., 17071482015225 + 204283788812944 = 4131765^2 + 14292788^2 .

It is not a de Polignac number, because 221355270828169 - 2¹¹ = 221355270826121 is a prime.

It is a super-2 number, since 2×221355270828169² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221355270828163) 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 2 ways as a sum of consecutive naturals, for example, 7439007 + ... + 22317019.

Almost surely, 2^{221355270828169} is an apocalyptic number.

221355270828169 is the 14878013-rd square number.

221355270828169 is the 7439007-th centered octagonal number.

It is an amenable number.

221355270828169 is a deficient number, since it is larger than the sum of its proper divisors (14878014).

221355270828169 is an frugal number, since it uses more digits than its factorization.

221355270828169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29756026 (or 14878013 counting only the distinct ones).

The product of its (nonzero) digits is 29030400, while the sum is 61.

The spelling of 221355270828169 in words is "two hundred twenty-one trillion, three hundred fifty-five billion, two hundred seventy million, eight hundred twenty-eight thousand, one hundred sixty-nine".