21030221120021 has 4 divisors (see below), whose sum is σ = 22137074863200. Its totient is φ = 19923367376844.

The previous prime is 21030221119967. The next prime is 21030221120039. The reversal of 21030221120021 is 12002112203012.

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 21030221120021 - 2¹⁰ = 21030221118997 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 (21030221120521) 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, 553426871561 + ... + 553426871598.

It is an arithmetic number, because the mean of its divisors is an integer number (5534268715800).

Almost surely, 2^{21030221120021} is an apocalyptic number.

It is an amenable number.

21030221120021 is a deficient number, since it is larger than the sum of its proper divisors (1106853743179).

21030221120021 is a wasteful number, since it uses less digits than its factorization.

21030221120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1106853743178.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21030221120021 its reverse (12002112203012), we get a palindrome (33032333323033).

The spelling of 21030221120021 in words is "twenty-one trillion, thirty billion, two hundred twenty-one million, one hundred twenty thousand, twenty-one".