1800002081 has 2 divisors, whose sum is σ = 1800002082. Its totient is φ = 1800002080.

The previous prime is 1800002053. The next prime is 1800002089. The reversal of 1800002081 is 1802000081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1583323681 + 216678400 = 39791^2 + 14720^2 .

It is a cyclic number.

It is not a de Polignac number, because 1800002081 - 2¹⁴ = 1799985697 is a prime.

It is a super-2 number, since 2×1800002081² = 6480014983208661122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1800002089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 900001040 + 900001041.

It is an arithmetic number, because the mean of its divisors is an integer number (900001041).

Almost surely, 2^1800002081 is an apocalyptic number.

It is an amenable number.

1800002081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1800002081 is an equidigital number, since it uses as much as digits as its factorization.

1800002081 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1800002081 is about 42426.4313960060. The cubic root of 1800002081 is about 1216.4408678946.

The spelling of 1800002081 in words is "one billion, eight hundred million, two thousand, eighty-one".