6720545 has 8 divisors (see below), whose sum is σ = 8685096. Its totient is φ = 4962816.

The previous prime is 6720533. The next prime is 6720589. The reversal of 6720545 is 5450276.

6720545 = 289² + 290² + ... + 353².

It can be written as a sum of positive squares in 4 ways, for example, as 22801 + 6697744 = 151^2 + 2588^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6720545 - 2⁶ = 6720481 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51632 + ... + 51761.

It is an arithmetic number, because the mean of its divisors is an integer number (1085637).

Almost surely, 2^6720545 is an apocalyptic number.

6720545 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6720545 is a deficient number, since it is larger than the sum of its proper divisors (1964551).

6720545 is a wasteful number, since it uses less digits than its factorization.

6720545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103411.

The product of its (nonzero) digits is 8400, while the sum is 29.

The square root of 6720545 is about 2592.4013963891. The cubic root of 6720545 is about 188.7128605494.

It can be divided in two parts, 6 and 720545, that multiplied together give a triangular number (4323270 = T₂₉₄₀).

The spelling of 6720545 in words is "six million, seven hundred twenty thousand, five hundred forty-five".