2505643985 has 16 divisors (see below), whose sum is σ = 3254516496. Its totient is φ = 1840919808.

The previous prime is 2505643961. The next prime is 2505644003. The reversal of 2505643985 is 5893465052.

2505643985 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 210946576 + 2294697409 = 14524^2 + 47903^2 .

It is not a de Polignac number, because 2505643985 - 2¹⁰ = 2505642961 is a prime.

It is a Duffinian number.

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, 85034 + ... + 110643.

It is an arithmetic number, because the mean of its divisors is an integer number (203407281).

Almost surely, 2^2505643985 is an apocalyptic number.

It is an amenable number.

2505643985 is a deficient number, since it is larger than the sum of its proper divisors (748872511).

2505643985 is a wasteful number, since it uses less digits than its factorization.

2505643985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195892.

The product of its (nonzero) digits is 1296000, while the sum is 47.

The square root of 2505643985 is about 50056.4080313400. The cubic root of 2505643985 is about 1358.2293828221.

The spelling of 2505643985 in words is "two billion, five hundred five million, six hundred forty-three thousand, nine hundred eighty-five".