3985837561 has 4 divisors (see below), whose sum is σ = 4220298612. Its totient is φ = 3751376512.

The previous prime is 3985837529. The next prime is 3985837577. The reversal of 3985837561 is 1657385893.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3338643961 + 647193600 = 57781^2 + 25440^2 .

It is a cyclic number.

It is not a de Polignac number, because 3985837561 - 2⁵ = 3985837529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3985837501) 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 3 ways as a sum of consecutive naturals, for example, 117230500 + ... + 117230533.

It is an arithmetic number, because the mean of its divisors is an integer number (1055074653).

Almost surely, 2^3985837561 is an apocalyptic number.

It is an amenable number.

3985837561 is a deficient number, since it is larger than the sum of its proper divisors (234461051).

3985837561 is a wasteful number, since it uses less digits than its factorization.

3985837561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234461050.

The product of its digits is 5443200, while the sum is 55.

The square root of 3985837561 is about 63133.4900112452. The cubic root of 3985837561 is about 1585.5253806694.

The spelling of 3985837561 in words is "three billion, nine hundred eighty-five million, eight hundred thirty-seven thousand, five hundred sixty-one".