211021001200021 has 4 divisors (see below), whose sum is σ = 211021036310700. Its totient is φ = 211020966089344.

The previous prime is 211021001200019. The next prime is 211021001200049. The reversal of 211021001200021 is 120002100120112.

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 29387132580100 + 181633868619921 = 5420990^2 + 13477161^2 .

It is a cyclic number.

It is not a de Polignac number, because 211021001200021 - 2¹ = 211021001200019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211021001199974 and 211021001200010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211021001200001) 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, 6008476 + ... + 21404293.

It is an arithmetic number, because the mean of its divisors is an integer number (52755259077675).

Almost surely, 2^{211021001200021} is an apocalyptic number.

It is an amenable number.

211021001200021 is a deficient number, since it is larger than the sum of its proper divisors (35110679).

211021001200021 is an equidigital number, since it uses as much as digits as its factorization.

211021001200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35110678.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 211021001200021 its reverse (120002100120112), we get a palindrome (331023101320133).

The spelling of 211021001200021 in words is "two hundred eleven trillion, twenty-one billion, one million, two hundred thousand, twenty-one".