6545685681 has 32 divisors (see below), whose sum is σ = 10033802240. Its totient is φ = 4213036800.

The previous prime is 6545685623. The next prime is 6545685683. The reversal of 6545685681 is 1865865456.

6545685681 is a `hidden beast` number, since 65 + 456 + 8 + 56 + 81 = 666.

6545685681 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6545685681 - 2⁶ = 6545685617 is a prime.

It is a super-2 number, since 2×6545685681² = 85692002068896867522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6545685683) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 353391 + ... + 371451.

It is an arithmetic number, because the mean of its divisors is an integer number (313556320).

Almost surely, 2^6545685681 is an apocalyptic number.

It is an amenable number.

6545685681 is a deficient number, since it is larger than the sum of its proper divisors (3488116559).

6545685681 is a wasteful number, since it uses less digits than its factorization.

6545685681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18534 (or 18528 counting only the distinct ones).

The product of its digits is 6912000, while the sum is 54.

The square root of 6545685681 is about 80905.4119388808. The cubic root of 6545685681 is about 1870.6177414246.

The spelling of 6545685681 in words is "six billion, five hundred forty-five million, six hundred eighty-five thousand, six hundred eighty-one".