221012105 has 4 divisors (see below), whose sum is σ = 265214532. Its totient is φ = 176809680.

The previous prime is 221012081. The next prime is 221012111. The reversal of 221012105 is 501210122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 63936016 + 157076089 = 7996^2 + 12533^2 .

It is not a de Polignac number, because 221012105 - 2¹⁰ = 221011081 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221012105.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22101206 + ... + 22101215.

It is an arithmetic number, because the mean of its divisors is an integer number (66303633).

Almost surely, 2^221012105 is an apocalyptic number.

It is an amenable number.

221012105 is a deficient number, since it is larger than the sum of its proper divisors (44202427).

221012105 is an equidigital number, since it uses as much as digits as its factorization.

221012105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44202426.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 221012105 is about 14866.4758769521. The cubic root of 221012105 is about 604.6053980343.

Adding to 221012105 its reverse (501210122), we get a palindrome (722222227).

The spelling of 221012105 in words is "two hundred twenty-one million, twelve thousand, one hundred five".