21021312111103 has 4 divisors (see below), whose sum is σ = 21021325009528. Its totient is φ = 21021299212680.

The previous prime is 21021312111071. The next prime is 21021312111143. The reversal of 21021312111103 is 30111121312012.

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 21021312111103 - 2⁵ = 21021312111071 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 (21021312111143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3578688 + ... + 7406053.

It is an arithmetic number, because the mean of its divisors is an integer number (5255331252382).

Almost surely, 2^{21021312111103} is an apocalyptic number.

21021312111103 is a deficient number, since it is larger than the sum of its proper divisors (12898425).

21021312111103 is a wasteful number, since it uses less digits than its factorization.

21021312111103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12898424.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 21021312111103 its reverse (30111121312012), we get a palindrome (51132433423115).

The spelling of 21021312111103 in words is "twenty-one trillion, twenty-one billion, three hundred twelve million, one hundred eleven thousand, one hundred three".