21010111102221 has 8 divisors (see below), whose sum is σ = 28021357076064. Its totient is φ = 14002802931600.

The previous prime is 21010111102213. The next prime is 21010111102229. The reversal of 21010111102221 is 12220111101012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21010111102213) and next prime (21010111102229).

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

It is not a de Polignac number, because 21010111102221 - 2³ = 21010111102213 is a prime.

It is a super-2 number, since 2×21010111102221² (a number of 27 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 21010111102221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010111102229) 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, 984438355 + ... + 984459696.

It is an arithmetic number, because the mean of its divisors is an integer number (3502669634508).

Almost surely, 2^{21010111102221} is an apocalyptic number.

It is an amenable number.

21010111102221 is a deficient number, since it is larger than the sum of its proper divisors (7011245973843).

21010111102221 is a wasteful number, since it uses less digits than its factorization.

21010111102221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1968901611.

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

Adding to 21010111102221 its reverse (12220111101012), we get a palindrome (33230222203233).

The spelling of 21010111102221 in words is "twenty-one trillion, ten billion, one hundred eleven million, one hundred two thousand, two hundred twenty-one".