21011000111 has 4 divisors (see below), whose sum is σ = 22246941312. Its totient is φ = 19775058912.

The previous prime is 21011000099. The next prime is 21011000119. The reversal of 21011000111 is 11100011012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21011000111 - 2²⁶ = 20943891247 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 (21011000119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 617970575 + ... + 617970608.

It is an arithmetic number, because the mean of its divisors is an integer number (5561735328).

Almost surely, 2^21011000111 is an apocalyptic number.

21011000111 is a deficient number, since it is larger than the sum of its proper divisors (1235941201).

21011000111 is a wasteful number, since it uses less digits than its factorization.

21011000111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235941200.

The product of its (nonzero) digits is 2, while the sum is 8.

Adding to 21011000111 its reverse (11100011012), we get a palindrome (32111011123).

The spelling of 21011000111 in words is "twenty-one billion, eleven million, one hundred eleven", and thus it is an aban number.