21111011101 has 4 divisors (see below), whose sum is σ = 21111486912. Its totient is φ = 21110535292.

The previous prime is 21111011099. The next prime is 21111011107. The reversal of 21111011101 is 10111011112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21111011101 - 2¹ = 21111011099 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 (21111011107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163621 + ... + 262666.

It is an arithmetic number, because the mean of its divisors is an integer number (5277871728).

Almost surely, 2^21111011101 is an apocalyptic number.

It is an amenable number.

21111011101 is a deficient number, since it is larger than the sum of its proper divisors (475811).

21111011101 is an equidigital number, since it uses as much as digits as its factorization.

21111011101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475810.

The product of its (nonzero) digits is 2, while the sum is 10.

Adding to 21111011101 its reverse (10111011112), we get a palindrome (31222022213).

It can be divided in two parts, 21111011 and 101, that added together give a palindrome (21111112).

The spelling of 21111011101 in words is "twenty-one billion, one hundred eleven million, eleven thousand, one hundred one".