2128199581 has 2 divisors, whose sum is σ = 2128199582. Its totient is φ = 2128199580.

The previous prime is 2128199573. The next prime is 2128199599. The reversal of 2128199581 is 1859918212.

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., 1267716025 + 860483556 = 35605^2 + 29334^2 .

It is a cyclic number.

It is not a de Polignac number, because 2128199581 - 2³ = 2128199573 is a prime.

It is a super-2 number, since 2×2128199581² = 9058466913137151122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2128199531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1064099790 + 1064099791.

It is an arithmetic number, because the mean of its divisors is an integer number (1064099791).

Almost surely, 2^2128199581 is an apocalyptic number.

It is an amenable number.

2128199581 is a deficient number, since it is larger than the sum of its proper divisors (1).

2128199581 is an equidigital number, since it uses as much as digits as its factorization.

2128199581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 46.

The square root of 2128199581 is about 46132.4135613995. The cubic root of 2128199581 is about 1286.2857285112.

The spelling of 2128199581 in words is "two billion, one hundred twenty-eight million, one hundred ninety-nine thousand, five hundred eighty-one".