6545721 has 16 divisors (see below), whose sum is σ = 10742144. Its totient is φ = 3452544.

The previous prime is 6545717. The next prime is 6545729. The reversal of 6545721 is 1275456.

6545721 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6545721 - 2² = 6545717 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6545729) 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, 11716 + ... + 12261.

It is an arithmetic number, because the mean of its divisors is an integer number (671384).

Almost surely, 2^6545721 is an apocalyptic number.

It is an amenable number.

6545721 is a deficient number, since it is larger than the sum of its proper divisors (4196423).

6545721 is a wasteful number, since it uses less digits than its factorization.

6545721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24000.

The product of its digits is 8400, while the sum is 30.

The square root of 6545721 is about 2558.4606700123. The cubic root of 6545721 is about 187.0621105892.

The spelling of 6545721 in words is "six million, five hundred forty-five thousand, seven hundred twenty-one".