2001220010081 has 2 divisors, whose sum is σ = 2001220010082. Its totient is φ = 2001220010080.

The previous prime is 2001220010077. The next prime is 2001220010129. The reversal of 2001220010081 is 1800100221002.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1929832185856 + 71387824225 = 1389184^2 + 267185^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001220010081 - 2² = 2001220010077 is a prime.

It is a super-2 number, since 2×2001220010081² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2001220010281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000610005040 + 1000610005041.

It is an arithmetic number, because the mean of its divisors is an integer number (1000610005041).

Almost surely, 2^{2001220010081} is an apocalyptic number.

It is an amenable number.

2001220010081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001220010081 is an equidigital number, since it uses as much as digits as its factorization.

2001220010081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2001220010081 its reverse (1800100221002), we get a palindrome (3801320231083).

The spelling of 2001220010081 in words is "two trillion, one billion, two hundred twenty million, ten thousand, eighty-one".