21001020021103 has 2 divisors, whose sum is σ = 21001020021104. Its totient is φ = 21001020021102.

The previous prime is 21001020021029. The next prime is 21001020021167. The reversal of 21001020021103 is 30112002010012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001020021103 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001020061103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500510010551 + 10500510010552.

It is an arithmetic number, because the mean of its divisors is an integer number (10500510010552).

Almost surely, 2^{21001020021103} is an apocalyptic number.

21001020021103 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001020021103 is an equidigital number, since it uses as much as digits as its factorization.

21001020021103 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21001020021103 its reverse (30112002010012), we get a palindrome (51113022031115).

The spelling of 21001020021103 in words is "twenty-one trillion, one billion, twenty million, twenty-one thousand, one hundred three".