6720109 has 4 divisors (see below), whose sum is σ = 7331040. Its totient is φ = 6109180.

The previous prime is 6720089. The next prime is 6720143. The reversal of 6720109 is 9010276.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-6720109 is a prime.

It is a Duffinian number.

6720109 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6720179) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 305449 + ... + 305470.

It is an arithmetic number, because the mean of its divisors is an integer number (1832760).

Almost surely, 2^6720109 is an apocalyptic number.

It is an amenable number.

6720109 is a deficient number, since it is larger than the sum of its proper divisors (610931).

6720109 is a wasteful number, since it uses less digits than its factorization.

6720109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610930.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 6720109 is about 2592.3173031093. The cubic root of 6720109 is about 188.7087795021.

The spelling of 6720109 in words is "six million, seven hundred twenty thousand, one hundred nine".