20012021212181 has 2 divisors, whose sum is σ = 20012021212182. Its totient is φ = 20012021212180.

The previous prime is 20012021212111. The next prime is 20012021212187. The reversal of 20012021212181 is 18121212021002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17174932390225 + 2837088821956 = 4144265^2 + 1684366^2 .

It is a cyclic number.

It is not a de Polignac number, because 20012021212181 - 2¹⁸ = 20012020950037 is a prime.

It is a super-2 number, since 2×20012021212181² (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 (20012021212187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006010606090 + 10006010606091.

It is an arithmetic number, because the mean of its divisors is an integer number (10006010606091).

Almost surely, 2^{20012021212181} is an apocalyptic number.

It is an amenable number.

20012021212181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20012021212181 is an equidigital number, since it uses as much as digits as its factorization.

20012021212181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 23.

Adding to 20012021212181 its reverse (18121212021002), we get a palindrome (38133233233183).

The spelling of 20012021212181 in words is "twenty trillion, twelve billion, twenty-one million, two hundred twelve thousand, one hundred eighty-one".