20211020002181 has 2 divisors, whose sum is σ = 20211020002182. Its totient is φ = 20211020002180.

The previous prime is 20211020002051. The next prime is 20211020002193. The reversal of 20211020002181 is 18120002011202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18107867451556 + 2103152550625 = 4255334^2 + 1450225^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211020002181 - 2¹⁴ = 20211019985797 is a prime.

It is a super-2 number, since 2×20211020002181² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211020002681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105510001090 + 10105510001091.

It is an arithmetic number, because the mean of its divisors is an integer number (10105510001091).

Almost surely, 2^{20211020002181} is an apocalyptic number.

It is an amenable number.

20211020002181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211020002181 is an equidigital number, since it uses as much as digits as its factorization.

20211020002181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 20211020002181 its reverse (18120002011202), we get a palindrome (38331022013383).

The spelling of 20211020002181 in words is "twenty trillion, two hundred eleven billion, twenty million, two thousand, one hundred eighty-one".