21112220012021 has 8 divisors (see below), whose sum is σ = 21133801378200. Its totient is φ = 21090649466880.

The previous prime is 21112220011979. The next prime is 21112220012029. The reversal of 21112220012021 is 12021002221112.

It can be written as a sum of positive squares in 4 ways, for example, as 242443972996 + 20869776039025 = 492386^2 + 4568345^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112220012021 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 (21112220012029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1201685 + ... + 6608213.

It is an arithmetic number, because the mean of its divisors is an integer number (2641725172275).

Almost surely, 2^{21112220012021} is an apocalyptic number.

It is an amenable number.

21112220012021 is a deficient number, since it is larger than the sum of its proper divisors (21581366179).

21112220012021 is a wasteful number, since it uses less digits than its factorization.

21112220012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5410519.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21112220012021 its reverse (12021002221112), we get a palindrome (33133222233133).

The spelling of 21112220012021 in words is "twenty-one trillion, one hundred twelve billion, two hundred twenty million, twelve thousand, twenty-one".