21010102021221 has 16 divisors (see below), whose sum is σ = 28924325283840. Its totient is φ = 13551531582960.

The previous prime is 21010102021211. The next prime is 21010102021231. The reversal of 21010102021221 is 12212020101012.

It is an interprime number because it is at equal distance from previous prime (21010102021211) and next prime (21010102021231).

It is not a de Polignac number, because 21010102021221 - 2⁷ = 21010102021093 is a prime.

It is a super-2 number, since 2×21010102021221² (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 21010102021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010102021211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27732115 + ... + 28479648.

It is an arithmetic number, because the mean of its divisors is an integer number (1807770330240).

Almost surely, 2^{21010102021221} is an apocalyptic number.

It is an amenable number.

21010102021221 is a deficient number, since it is larger than the sum of its proper divisors (7914223262619).

21010102021221 is a wasteful number, since it uses less digits than its factorization.

21010102021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56215816.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21010102021221 its reverse (12212020101012), we get a palindrome (33222122122233).

The spelling of 21010102021221 in words is "twenty-one trillion, ten billion, one hundred two million, twenty-one thousand, two hundred twenty-one".