21020002102221 has 32 divisors (see below), whose sum is σ = 28446869224320. Its totient is φ = 13803731251200.

The previous prime is 21020002102159. The next prime is 21020002102243. The reversal of 21020002102221 is 12220120002012.

It is not a de Polignac number, because 21020002102221 - 2¹⁸ = 21020001840077 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020002102221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020002102721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1721392806 + ... + 1721405016.

It is an arithmetic number, because the mean of its divisors is an integer number (888964663260).

Almost surely, 2^{21020002102221} is an apocalyptic number.

It is an amenable number.

21020002102221 is a deficient number, since it is larger than the sum of its proper divisors (7426867122099).

21020002102221 is a wasteful number, since it uses less digits than its factorization.

21020002102221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21677.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21020002102221 its reverse (12220120002012), we get a palindrome (33240122104233).

The spelling of 21020002102221 in words is "twenty-one trillion, twenty billion, two million, one hundred two thousand, two hundred twenty-one".