21010012021111 has 12 divisors (see below), whose sum is σ = 21262976223192. Its totient is φ = 20760018555584.

The previous prime is 21010012021051. The next prime is 21010012021127. The reversal of 21010012021111 is 11112021001012.

It is a happy number.

It is not a de Polignac number, because 21010012021111 - 2¹¹ = 21010012019063 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010012021091 and 21010012021100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010012021151) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10937760 + ... + 12714346.

It is an arithmetic number, because the mean of its divisors is an integer number (1771914685266).

Almost surely, 2^{21010012021111} is an apocalyptic number.

21010012021111 is a deficient number, since it is larger than the sum of its proper divisors (252964202081).

21010012021111 is an equidigital number, since it uses as much as digits as its factorization.

21010012021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1778258 (or 1778169 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21010012021111 its reverse (11112021001012), we get a palindrome (32122033022123).

The spelling of 21010012021111 in words is "twenty-one trillion, ten billion, twelve million, twenty-one thousand, one hundred eleven".