21012201121111 has 16 divisors (see below), whose sum is σ = 21550736541600. Its totient is φ = 20474915097600.

The previous prime is 21012201121081. The next prime is 21012201121117. The reversal of 21012201121111 is 11112110221012.

It is a cyclic number.

It is not a de Polignac number, because 21012201121111 - 2¹³ = 21012201112919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012201121117) 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, 190498885 + ... + 190609153.

It is an arithmetic number, because the mean of its divisors is an integer number (1346921033850).

Almost surely, 2^{21012201121111} is an apocalyptic number.

21012201121111 is a deficient number, since it is larger than the sum of its proper divisors (538535420489).

21012201121111 is a wasteful number, since it uses less digits than its factorization.

21012201121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115890.

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

Adding to 21012201121111 its reverse (11112110221012), we get a palindrome (32124311342123).

Subtracting from 21012201121111 its reverse (11112110221012), we obtain a palindrome (9900090900099).

The spelling of 21012201121111 in words is "twenty-one trillion, twelve billion, two hundred one million, one hundred twenty-one thousand, one hundred eleven".