1818202081 has 2 divisors, whose sum is σ = 1818202082. Its totient is φ = 1818202080.

The previous prime is 1818202079. The next prime is 1818202103. The reversal of 1818202081 is 1802028181.

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., 1186182481 + 632019600 = 34441^2 + 25140^2 .

It is a cyclic number.

It is not a de Polignac number, because 1818202081 - 2¹ = 1818202079 is a prime.

It is a super-2 number, since 2×1818202081² = 6611717614705461122, which contains 22 as substring.

Together with 1818202079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1818202181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 909101040 + 909101041.

It is an arithmetic number, because the mean of its divisors is an integer number (909101041).

Almost surely, 2^1818202081 is an apocalyptic number.

It is an amenable number.

1818202081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1818202081 is an equidigital number, since it uses as much as digits as its factorization.

1818202081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2048, while the sum is 31.

The square root of 1818202081 is about 42640.3808730644. The cubic root of 1818202081 is about 1220.5269785112.

The spelling of 1818202081 in words is "one billion, eight hundred eighteen million, two hundred two thousand, eighty-one".