221001111212111 has 4 divisors (see below), whose sum is σ = 222464694730224. Its totient is φ = 219537527694000.

The previous prime is 221001111212017. The next prime is 221001111212131. The reversal of 221001111212111 is 111212111100122.

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

It is a cyclic number.

It is not a de Polignac number, because 221001111212111 - 2¹⁰ = 221001111211087 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 221001111212111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001111212131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 731791758830 + ... + 731791759131.

It is an arithmetic number, because the mean of its divisors is an integer number (55616173682556).

Almost surely, 2^{221001111212111} is an apocalyptic number.

221001111212111 is a deficient number, since it is larger than the sum of its proper divisors (1463583518113).

221001111212111 is a wasteful number, since it uses less digits than its factorization.

221001111212111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1463583518112.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 221001111212111 its reverse (111212111100122), we get a palindrome (332213222312233).

The spelling of 221001111212111 in words is "two hundred twenty-one trillion, one billion, one hundred eleven million, two hundred twelve thousand, one hundred eleven".