21221023103021 has 4 divisors (see below), whose sum is σ = 24252597832032. Its totient is φ = 18189448374012.

The previous prime is 21221023103017. The next prime is 21221023103083. The reversal of 21221023103021 is 12030132012212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21221023103021 - 2² = 21221023103017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221023102984 and 21221023103002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221023102021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1515787364495 + ... + 1515787364508.

It is an arithmetic number, because the mean of its divisors is an integer number (6063149458008).

Almost surely, 2^{21221023103021} is an apocalyptic number.

It is an amenable number.

21221023103021 is a deficient number, since it is larger than the sum of its proper divisors (3031574729011).

21221023103021 is an equidigital number, since it uses as much as digits as its factorization.

21221023103021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3031574729010.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21221023103021 its reverse (12030132012212), we get a palindrome (33251155115233).

The spelling of 21221023103021 in words is "twenty-one trillion, two hundred twenty-one billion, twenty-three million, one hundred three thousand, twenty-one".