21011201111 has 8 divisors (see below), whose sum is σ = 21801366144. Its totient is φ = 20228060160.

The previous prime is 21011201093. The next prime is 21011201149. The reversal of 21011201111 is 11110211012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011201111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011201092 and 21011201101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011201171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1749926 + ... + 1761891.

It is an arithmetic number, because the mean of its divisors is an integer number (2725170768).

Almost surely, 2^21011201111 is an apocalyptic number.

21011201111 is a deficient number, since it is larger than the sum of its proper divisors (790165033).

21011201111 is a wasteful number, since it uses less digits than its factorization.

21011201111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3512041.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21011201111 its reverse (11110211012), we get a palindrome (32121412123).

Subtracting from 21011201111 its reverse (11110211012), we obtain a palindrome (9900990099).

The spelling of 21011201111 in words is "twenty-one billion, eleven million, two hundred one thousand, one hundred eleven".