6518921985 has 16 divisors (see below), whose sum is σ = 11589194880. Its totient is φ = 3476758320.

The previous prime is 6518921933. The next prime is 6518921989. The reversal of 6518921985 is 5891298156.

It is not a de Polignac number, because 6518921985 - 2¹¹ = 6518919937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6518921989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24144021 + ... + 24144290.

It is an arithmetic number, because the mean of its divisors is an integer number (724324680).

Almost surely, 2^6518921985 is an apocalyptic number.

It is an amenable number.

6518921985 is a deficient number, since it is larger than the sum of its proper divisors (5070272895).

6518921985 is a wasteful number, since it uses less digits than its factorization.

6518921985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48288325 (or 48288319 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 54.

The square root of 6518921985 is about 80739.8413733889. The cubic root of 6518921985 is about 1868.0647604014.

The spelling of 6518921985 in words is "six billion, five hundred eighteen million, nine hundred twenty-one thousand, nine hundred eighty-five".