21002111212 has 12 divisors (see below), whose sum is σ = 36809471160. Its totient is φ = 10485119456.

The previous prime is 21002111209. The next prime is 21002111231. The reversal of 21002111212 is 21211120012.

It is a super-2 number, since 2×21002111212² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002111192 and 21002111201.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3981073 + ... + 3986344.

It is an arithmetic number, because the mean of its divisors is an integer number (3067455930).

Almost surely, 2^21002111212 is an apocalyptic number.

It is an amenable number.

21002111212 is a deficient number, since it is larger than the sum of its proper divisors (15807359948).

21002111212 is a wasteful number, since it uses less digits than its factorization.

21002111212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7968080 (or 7968078 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21002111212 its reverse (21211120012), we get a palindrome (42213231224).

The spelling of 21002111212 in words is "twenty-one billion, two million, one hundred eleven thousand, two hundred twelve".