21000002111 has 12 divisors (see below), whose sum is σ = 24178299624. Its totient is φ = 18086122800.

The previous prime is 21000002083. The next prime is 21000002129. The reversal of 21000002111 is 11120000012.

It is not a de Polignac number, because 21000002111 - 2¹⁸ = 20999739967 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 (21000002141) 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, 2640200 + ... + 2648141.

It is an arithmetic number, because the mean of its divisors is an integer number (2014858302).

Almost surely, 2^21000002111 is an apocalyptic number.

21000002111 is a deficient number, since it is larger than the sum of its proper divisors (3178297513).

21000002111 is a wasteful number, since it uses less digits than its factorization.

21000002111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5288390 (or 5288371 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21000002111 its reverse (11120000012), we get a palindrome (32120002123).

The spelling of 21000002111 in words is "twenty-one billion, two thousand, one hundred eleven".