1210021111221 has 8 divisors (see below), whose sum is σ = 1737466211040. Its totient is φ = 744628376112.

The previous prime is 1210021111219. The next prime is 1210021111223. The reversal of 1210021111221 is 1221111200121.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1210021111219) and next prime (1210021111223).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1210021111221 - 2¹ = 1210021111219 is a prime.

It is a super-2 number, since 2×1210021111221² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1210021111221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210021111223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15513091131 + ... + 15513091208.

It is an arithmetic number, because the mean of its divisors is an integer number (217183276380).

Almost surely, 2^{1210021111221} is an apocalyptic number.

It is an amenable number.

1210021111221 is a deficient number, since it is larger than the sum of its proper divisors (527445099819).

1210021111221 is a wasteful number, since it uses less digits than its factorization.

1210021111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31026182355.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1210021111221 its reverse (1221111200121), we get a palindrome (2431132311342).

The spelling of 1210021111221 in words is "one trillion, two hundred ten billion, twenty-one million, one hundred eleven thousand, two hundred twenty-one".