6545181821 has 16 divisors (see below), whose sum is σ = 6771643200. Its totient is φ = 6322166400.

The previous prime is 6545181763. The next prime is 6545181847. The reversal of 6545181821 is 1281815456.

It is a cyclic number.

It is not a de Polignac number, because 6545181821 - 2⁶ = 6545181757 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6545181121) 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, 2386511 + ... + 2389251.

It is an arithmetic number, because the mean of its divisors is an integer number (423227700).

Almost surely, 2^6545181821 is an apocalyptic number.

It is an amenable number.

6545181821 is a deficient number, since it is larger than the sum of its proper divisors (226461379).

6545181821 is a wasteful number, since it uses less digits than its factorization.

6545181821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3340.

The product of its digits is 76800, while the sum is 41.

The square root of 6545181821 is about 80902.2979957924. The cubic root of 6545181821 is about 1870.5697427027.

The spelling of 6545181821 in words is "six billion, five hundred forty-five million, one hundred eighty-one thousand, eight hundred twenty-one".