21012111221101 has 24 divisors (see below), whose sum is σ = 28715852307744. Its totient is φ = 15113606467680.

The previous prime is 21012111221009. The next prime is 21012111221107. The reversal of 21012111221101 is 10112211121012.

It is not a de Polignac number, because 21012111221101 - 2¹¹ = 21012111219053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012111221107) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1499358715 + ... + 1499372728.

It is an arithmetic number, because the mean of its divisors is an integer number (1196493846156).

Almost surely, 2^{21012111221101} is an apocalyptic number.

It is an amenable number.

21012111221101 is a deficient number, since it is larger than the sum of its proper divisors (7703741086643).

21012111221101 is a wasteful number, since it uses less digits than its factorization.

21012111221101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2998731481 (or 2998731474 counting only the distinct ones).

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

Adding to 21012111221101 its reverse (10112211121012), we get a palindrome (31124322342113).

It can be divided in two parts, 21012111 and 221101, that added together give a palindrome (21233212).

The spelling of 21012111221101 in words is "twenty-one trillion, twelve billion, one hundred eleven million, two hundred twenty-one thousand, one hundred one".