21001101121111 has 16 divisors (see below), whose sum is σ = 21082576320000. Its totient is φ = 20919774972096.

The previous prime is 21001101121061. The next prime is 21001101121129. The reversal of 21001101121111 is 11112110110012.

It is a cyclic number.

It is not a de Polignac number, because 21001101121111 - 2¹⁵ = 21001101088343 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001101121091 and 21001101121100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001101121171) 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, 2622183675 + ... + 2622191683.

It is an arithmetic number, because the mean of its divisors is an integer number (1317661020000).

Almost surely, 2^{21001101121111} is an apocalyptic number.

21001101121111 is a deficient number, since it is larger than the sum of its proper divisors (81475198889).

21001101121111 is a wasteful number, since it uses less digits than its factorization.

21001101121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16086.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21001101121111 its reverse (11112110110012), we get a palindrome (32113211231123).

The spelling of 21001101121111 in words is "twenty-one trillion, one billion, one hundred one million, one hundred twenty-one thousand, one hundred eleven".