3261561985 has 16 divisors (see below), whose sum is σ = 4271141952. Its totient is φ = 2371233600.

The previous prime is 3261561917. The next prime is 3261561991. The reversal of 3261561985 is 5891651623.

It is not a de Polignac number, because 3261561985 - 2¹¹ = 3261559937 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 186382 + ... + 203128.

It is an arithmetic number, because the mean of its divisors is an integer number (266946372).

Almost surely, 2^3261561985 is an apocalyptic number.

It is an amenable number.

3261561985 is a deficient number, since it is larger than the sum of its proper divisors (1009579967).

3261561985 is a wasteful number, since it uses less digits than its factorization.

3261561985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20304.

The product of its digits is 388800, while the sum is 46.

The square root of 3261561985 is about 57110.0865434469. The cubic root of 3261561985 is about 1483.0024853445.

The spelling of 3261561985 in words is "three billion, two hundred sixty-one million, five hundred sixty-one thousand, nine hundred eighty-five".