21012111012103 has 16 divisors (see below), whose sum is σ = 21605891275296. Its totient is φ = 20419705152000.

The previous prime is 21012111012017. The next prime is 21012111012107. The reversal of 21012111012103 is 30121011121012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21012111012103 - 2²⁵ = 21012077457671 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 (21012111012107) 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, 129054675 + ... + 129217387.

It is an arithmetic number, because the mean of its divisors is an integer number (1350368204706).

Almost surely, 2^{21012111012103} is an apocalyptic number.

21012111012103 is a deficient number, since it is larger than the sum of its proper divisors (593780263193).

21012111012103 is a wasteful number, since it uses less digits than its factorization.

21012111012103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166914.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 21012111012103 its reverse (30121011121012), we get a palindrome (51133122133115).

The spelling of 21012111012103 in words is "twenty-one trillion, twelve billion, one hundred eleven million, twelve thousand, one hundred three".