21112020020009 has 4 divisors (see below), whose sum is σ = 21171827442516. Its totient is φ = 21052212597504.

The previous prime is 21112020019991. The next prime is 21112020020041. The reversal of 21112020020009 is 90002002021112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16753958785600 + 4358061234409 = 4093160^2 + 2087597^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112020020009 - 2¹² = 21112020015913 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21112020020209) 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, 29903710724 + ... + 29903711429.

It is an arithmetic number, because the mean of its divisors is an integer number (5292956860629).

Almost surely, 2^{21112020020009} is an apocalyptic number.

It is an amenable number.

21112020020009 is a deficient number, since it is larger than the sum of its proper divisors (59807422507).

21112020020009 is an equidigital number, since it uses as much as digits as its factorization.

21112020020009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59807422506.

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 21112020020009 in words is "twenty-one trillion, one hundred twelve billion, twenty million, twenty thousand, nine".