221166505 has 32 divisors (see below), whose sum is σ = 324269568. Its totient is φ = 141504000.

The previous prime is 221166497. The next prime is 221166523. The reversal of 221166505 is 505661122.

It is not a de Polignac number, because 221166505 - 2³ = 221166497 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29655 + ... + 36355.

It is an arithmetic number, because the mean of its divisors is an integer number (10133424).

Almost surely, 2^221166505 is an apocalyptic number.

It is an amenable number.

221166505 is a deficient number, since it is larger than the sum of its proper divisors (103103063).

221166505 is a wasteful number, since it uses less digits than its factorization.

221166505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6777.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 221166505 is about 14871.6678620792. The cubic root of 221166505 is about 604.7461585647.

The spelling of 221166505 in words is "two hundred twenty-one million, one hundred sixty-six thousand, five hundred five".