21012101111 has 8 divisors (see below), whose sum is σ = 21545966400. Its totient is φ = 20479253760.

The previous prime is 21012101093. The next prime is 21012101251. The reversal of 21012101111 is 11110121012.

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

It is a cyclic number.

It is not a de Polignac number, because 21012101111 - 2²² = 21007906807 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012101092 and 21012101101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012101611) 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, 212591 + ... + 295328.

It is an arithmetic number, because the mean of its divisors is an integer number (2693245800).

Almost surely, 2^21012101111 is an apocalyptic number.

21012101111 is a deficient number, since it is larger than the sum of its proper divisors (533865289).

21012101111 is a wasteful number, since it uses less digits than its factorization.

21012101111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508969.

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

Adding to 21012101111 its reverse (11110121012), we get a palindrome (32122222123).

The spelling of 21012101111 in words is "twenty-one billion, twelve million, one hundred one thousand, one hundred eleven".