21100112011021 has 4 divisors (see below), whose sum is σ = 21100122379612. Its totient is φ = 21100101642432.

The previous prime is 21100112011003. The next prime is 21100112011031. The reversal of 21100112011021 is 12011021100112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6894668092900 + 14205443918121 = 2625770^2 + 3769011^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21100112011021 is a prime.

It is a super-3 number, since 3×21100112011021³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21100112010992 and 21100112011010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100112011031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1013100 + ... + 6574693.

It is an arithmetic number, because the mean of its divisors is an integer number (5275030594903).

Almost surely, 2^{21100112011021} is an apocalyptic number.

It is an amenable number.

21100112011021 is a deficient number, since it is larger than the sum of its proper divisors (10368591).

21100112011021 is an equidigital number, since it uses as much as digits as its factorization.

21100112011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10368590.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21100112011021 its reverse (12011021100112), we get a palindrome (33111133111133).

The spelling of 21100112011021 in words is "twenty-one trillion, one hundred billion, one hundred twelve million, eleven thousand, twenty-one".