2001022081 has 2 divisors, whose sum is σ = 2001022082. Its totient is φ = 2001022080.

The previous prime is 2001022073. The next prime is 2001022099. The reversal of 2001022081 is 1802201002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1264442481 + 736579600 = 35559^2 + 27140^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001022081 - 2³ = 2001022073 is a prime.

It is a super-2 number, since 2×2001022081² = 8008178737299141122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2001022061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000511040 + 1000511041.

It is an arithmetic number, because the mean of its divisors is an integer number (1000511041).

Almost surely, 2^2001022081 is an apocalyptic number.

It is an amenable number.

2001022081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001022081 is an equidigital number, since it uses as much as digits as its factorization.

2001022081 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 16.

The square root of 2001022081 is about 44732.7853033991. The cubic root of 2001022081 is about 1260.1356369059.

Adding to 2001022081 its reverse (1802201002), we get a palindrome (3803223083).

The spelling of 2001022081 in words is "two billion, one million, twenty-two thousand, eighty-one".