21213111103 has 4 divisors (see below), whose sum is σ = 21423142008. Its totient is φ = 21003080200.

The previous prime is 21213111097. The next prime is 21213111109. The reversal of 21213111103 is 30111131212.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (21213111097) and next prime (21213111109).

It is a cyclic number.

It is not a de Polignac number, because 21213111103 - 2⁹ = 21213110591 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 (21213111109) 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, 105015301 + ... + 105015502.

It is an arithmetic number, because the mean of its divisors is an integer number (5355785502).

Almost surely, 2^21213111103 is an apocalyptic number.

21213111103 is a deficient number, since it is larger than the sum of its proper divisors (210030905).

21213111103 is a wasteful number, since it uses less digits than its factorization.

21213111103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210030904.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21213111103 its reverse (30111131212), we get a palindrome (51324242315).

The spelling of 21213111103 in words is "twenty-one billion, two hundred thirteen million, one hundred eleven thousand, one hundred three".