21001012021023 has 4 divisors (see below), whose sum is σ = 28001349361368. Its totient is φ = 14000674680680.

The previous prime is 21001012021013. The next prime is 21001012021061. The reversal of 21001012021023 is 32012021010012.

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 21001012021023 - 2⁵ = 21001012020991 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001012020993 and 21001012021011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001012021013) 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, 3500168670168 + ... + 3500168670173.

It is an arithmetic number, because the mean of its divisors is an integer number (7000337340342).

Almost surely, 2^{21001012021023} is an apocalyptic number.

21001012021023 is a deficient number, since it is larger than the sum of its proper divisors (7000337340345).

21001012021023 is an equidigital number, since it uses as much as digits as its factorization.

21001012021023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7000337340344.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21001012021023 its reverse (32012021010012), we get a palindrome (53013033031035).

The spelling of 21001012021023 in words is "twenty-one trillion, one billion, twelve million, twenty-one thousand, twenty-three".