2478509685 has 20 divisors (see below), whose sum is σ = 4442958828. Its totient is φ = 1321871616.

The previous prime is 2478509681. The next prime is 2478509687. The reversal of 2478509685 is 5869058742.

2478509685 is a `hidden beast` number, since 2 + 4 + 78 + 509 + 68 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1161037476 + 1317472209 = 34074^2 + 36297^2 .

It is not a de Polignac number, because 2478509685 - 2² = 2478509681 is a prime.

It is a super-2 number, since 2×2478509685² = 12286020517277598450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2478509681) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3059484 + ... + 3060293.

Almost surely, 2^2478509685 is an apocalyptic number.

It is an amenable number.

2478509685 is a deficient number, since it is larger than the sum of its proper divisors (1964449143).

2478509685 is an equidigital number, since it uses as much as digits as its factorization.

2478509685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6119794 (or 6119785 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 54.

The square root of 2478509685 is about 49784.6330206420. The cubic root of 2478509685 is about 1353.3086989390.

The spelling of 2478509685 in words is "two billion, four hundred seventy-eight million, five hundred nine thousand, six hundred eighty-five".