3873991581 has 6 divisors (see below), whose sum is σ = 5595765630. Its totient is φ = 2582661048.

The previous prime is 3873991573. The next prime is 3873991609. The reversal of 3873991581 is 1851993783.

It can be written as a sum of positive squares in only one way, i.e., 3414532356 + 459459225 = 58434^2 + 21435^2 .

It is not a de Polignac number, because 3873991581 - 2³ = 3873991573 is a prime.

It is a super-2 number, since 2×3873991581² = 30015621539317759122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3873991571) 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 in 5 ways as a sum of consecutive naturals, for example, 215221746 + ... + 215221763.

It is an arithmetic number, because the mean of its divisors is an integer number (932627605).

Almost surely, 2^3873991581 is an apocalyptic number.

It is an amenable number.

3873991581 is a deficient number, since it is larger than the sum of its proper divisors (1721774049).

3873991581 is a wasteful number, since it uses less digits than its factorization.

3873991581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430443515 (or 430443512 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 54.

The square root of 3873991581 is about 62241.3976465825. The cubic root of 3873991581 is about 1570.5540637109.

The spelling of 3873991581 in words is "three billion, eight hundred seventy-three million, nine hundred ninety-one thousand, five hundred eighty-one".