21120001111021 has 4 divisors (see below), whose sum is σ = 21175726708000. Its totient is φ = 21064275514044.

The previous prime is 21120001111019. The next prime is 21120001111063. The reversal of 21120001111021 is 12011110002112.

It is a happy number.

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 21120001111021 - 2¹ = 21120001111019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120001110992 and 21120001111010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120001151021) 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, 27862797921 + ... + 27862798678.

It is an arithmetic number, because the mean of its divisors is an integer number (5293931677000).

Almost surely, 2^{21120001111021} is an apocalyptic number.

It is an amenable number.

21120001111021 is a deficient number, since it is larger than the sum of its proper divisors (55725596979).

21120001111021 is an equidigital number, since it uses as much as digits as its factorization.

21120001111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55725596978.

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

Adding to 21120001111021 its reverse (12011110002112), we get a palindrome (33131111113133).

The spelling of 21120001111021 in words is "twenty-one trillion, one hundred twenty billion, one million, one hundred eleven thousand, twenty-one".