2045518681 has 2 divisors, whose sum is σ = 2045518682. Its totient is φ = 2045518680.

The previous prime is 2045518669. The next prime is 2045518691. The reversal of 2045518681 is 1868155402.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1641870400 + 403648281 = 40520^2 + 20091^2 .

It is a cyclic number.

It is not a de Polignac number, because 2045518681 - 2¹⁷ = 2045387609 is a prime.

It is a super-2 number, since 2×2045518681² = 8368293348639959522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2045518691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1022759340 + 1022759341.

It is an arithmetic number, because the mean of its divisors is an integer number (1022759341).

Almost surely, 2^2045518681 is an apocalyptic number.

It is an amenable number.

2045518681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2045518681 is an equidigital number, since it uses as much as digits as its factorization.

2045518681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 76800, while the sum is 40.

The square root of 2045518681 is about 45227.4107262399. The cubic root of 2045518681 is about 1269.4077634225.

The spelling of 2045518681 in words is "two billion, forty-five million, five hundred eighteen thousand, six hundred eighty-one".