211010010020021 has 4 divisors (see below), whose sum is σ = 213380909009100. Its totient is φ = 208639111030944.

The previous prime is 211010010020011. The next prime is 211010010020041. The reversal of 211010010020021 is 120020010010112.

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 87754740062500 + 123255269957521 = 9367750^2 + 11102039^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211010010020021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211010010019984 and 211010010020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211010010020011) 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, 1185449494406 + ... + 1185449494583.

It is an arithmetic number, because the mean of its divisors is an integer number (53345227252275).

Almost surely, 2^{211010010020021} is an apocalyptic number.

It is an amenable number.

211010010020021 is a deficient number, since it is larger than the sum of its proper divisors (2370898989079).

211010010020021 is an equidigital number, since it uses as much as digits as its factorization.

211010010020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2370898989078.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 211010010020021 its reverse (120020010010112), we get a palindrome (331030020030133).

Subtracting from 211010010020021 its reverse (120020010010112), we obtain a palindrome (90990000009909).

The spelling of 211010010020021 in words is "two hundred eleven trillion, ten billion, ten million, twenty thousand, twenty-one".