21211212103 has 16 divisors (see below), whose sum is σ = 23243107680. Its totient is φ = 19267024896.

The previous prime is 21211212083. The next prime is 21211212107. The reversal of 21211212103 is 30121211212.

It is a cyclic number.

It is not a de Polignac number, because 21211212103 - 2²⁵ = 21177657671 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 (21211212107) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1389076 + ... + 1404262.

It is an arithmetic number, because the mean of its divisors is an integer number (1452694230).

Almost surely, 2^21211212103 is an apocalyptic number.

21211212103 is a deficient number, since it is larger than the sum of its proper divisors (2031895577).

21211212103 is a wasteful number, since it uses less digits than its factorization.

21211212103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18066.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21211212103 its reverse (30121211212), we get a palindrome (51332423315).

The spelling of 21211212103 in words is "twenty-one billion, two hundred eleven million, two hundred twelve thousand, one hundred three".