221165966 has 32 divisors (see below), whose sum is σ = 411985920. Its totient is φ = 86896800.

The previous prime is 221165939. The next prime is 221165981. The reversal of 221165966 is 669561122.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5165 + ... + 21656.

It is an arithmetic number, because the mean of its divisors is an integer number (12874560).

Almost surely, 2^221165966 is an apocalyptic number.

221165966 is a deficient number, since it is larger than the sum of its proper divisors (190819954).

221165966 is a wasteful number, since it uses less digits than its factorization.

221165966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26880.

The product of its digits is 38880, while the sum is 38.

The square root of 221165966 is about 14871.6497403617. The cubic root of 221165966 is about 604.7456672932.

It can be divided in two parts, 22116 and 5966, that added together give a palindrome (28082).

The spelling of 221165966 in words is "two hundred twenty-one million, one hundred sixty-five thousand, nine hundred sixty-six".