21012000111 has 12 divisors (see below), whose sum is σ = 30483205480. Its totient is φ = 13946828400.

The previous prime is 21012000109. The next prime is 21012000133. The reversal of 21012000111 is 11100021012.

It is a happy number.

It is not a de Polignac number, because 21012000111 - 2¹ = 21012000109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012000093 and 21012000102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012000101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5095465 + ... + 5099586.

Almost surely, 2^21012000111 is an apocalyptic number.

21012000111 is a deficient number, since it is larger than the sum of its proper divisors (9471205369).

21012000111 is a wasteful number, since it uses less digits than its factorization.

21012000111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10195286 (or 10195283 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21012000111 its reverse (11100021012), we get a palindrome (32112021123).

The spelling of 21012000111 in words is "twenty-one billion, twelve million, one hundred eleven", and thus it is an aban number.