1859999081 has 2 divisors, whose sum is σ = 1859999082. Its totient is φ = 1859999080.

The previous prime is 1859999077. The next prime is 1859999107. The reversal of 1859999081 is 1809999581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1797336025 + 62663056 = 42395^2 + 7916^2 .

It is a cyclic number.

It is not a de Polignac number, because 1859999081 - 2² = 1859999077 is a prime.

It is a super-2 number, since 2×1859999081² = 6919193162641689122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1859999081.

It is not a weakly prime, because it can be changed into another prime (1859999021) 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, 929999540 + 929999541.

It is an arithmetic number, because the mean of its divisors is an integer number (929999541).

Almost surely, 2^1859999081 is an apocalyptic number.

It is an amenable number.

1859999081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1859999081 is an equidigital number, since it uses as much as digits as its factorization.

1859999081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2099520, while the sum is 59.

The square root of 1859999081 is about 43127.7066512932. The cubic root of 1859999081 is about 1229.8087439203.

The spelling of 1859999081 in words is "one billion, eight hundred fifty-nine million, nine hundred ninety-nine thousand, eighty-one".