20210020984781 has 2 divisors, whose sum is σ = 20210020984782. Its totient is φ = 20210020984780.

The previous prime is 20210020984729. The next prime is 20210020984789. The reversal of 20210020984781 is 18748902001202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10339176580681 + 9870844404100 = 3215459^2 + 3141790^2 .

It is a cyclic number.

It is not a de Polignac number, because 20210020984781 - 2²² = 20210016790477 is a prime.

It is a super-2 number, since 2×20210020984781² (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 (20210020984789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105010492390 + 10105010492391.

It is an arithmetic number, because the mean of its divisors is an integer number (10105010492391).

Almost surely, 2^{20210020984781} is an apocalyptic number.

It is an amenable number.

20210020984781 is a deficient number, since it is larger than the sum of its proper divisors (1).

20210020984781 is an equidigital number, since it uses as much as digits as its factorization.

20210020984781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129024, while the sum is 44.

Adding to 20210020984781 its reverse (18748902001202), we get a palindrome (38958922985983).

The spelling of 20210020984781 in words is "twenty trillion, two hundred ten billion, twenty million, nine hundred eighty-four thousand, seven hundred eighty-one".