221166776792329 has 3 divisors (see below), whose sum is σ = 221166791664007. Its totient is φ = 221166761920652.

The previous prime is 221166776792281. The next prime is 221166776792341. The reversal of 221166776792329 is 923297677661122.

The square root of 221166776792329 is 14871677.

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., 25238114300025 + 195928662492304 = 5023755^2 + 13997452^2 .

It is not a de Polignac number, because 221166776792329 - 2⁷ = 221166776792201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221166776798329) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7435839 + ... + 22307515.

Almost surely, 2^{221166776792329} is an apocalyptic number.

221166776792329 is the 14871677-th square number.

221166776792329 is the 7435839-th centered octagonal number.

It is an amenable number.

221166776792329 is a deficient number, since it is larger than the sum of its proper divisors (14871678).

221166776792329 is an frugal number, since it uses more digits than its factorization.

221166776792329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29743354 (or 14871677 counting only the distinct ones).

The product of its digits is 288054144, while the sum is 70.

The spelling of 221166776792329 in words is "two hundred twenty-one trillion, one hundred sixty-six billion, seven hundred seventy-six million, seven hundred ninety-two thousand, three hundred twenty-nine".