21201000111 has 48 divisors (see below), whose sum is σ = 31723494400. Its totient is φ = 13633583040.

The previous prime is 21201000091. The next prime is 21201000113. The reversal of 21201000111 is 11100010212.

It is a happy number.

It is not a de Polignac number, because 21201000111 - 2¹⁸ = 21200737967 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 = 21201000093 and 21201000102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201000113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 30681276 + ... + 30681966.

Almost surely, 2^21201000111 is an apocalyptic number.

21201000111 is a deficient number, since it is larger than the sum of its proper divisors (10522494289).

21201000111 is a wasteful number, since it uses less digits than its factorization.

21201000111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1396 (or 1393 counting only the distinct ones).

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

Adding to 21201000111 its reverse (11100010212), we get a palindrome (32301010323).

The spelling of 21201000111 in words is "twenty-one billion, two hundred one million, one hundred eleven", and thus it is an aban number.