6721613 has 8 divisors (see below), whose sum is σ = 7148160. Its totient is φ = 6298560.

The previous prime is 6721609. The next prime is 6721661. The reversal of 6721613 is 3161276.

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 6721613 - 2² = 6721609 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6721213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3878 + ... + 5336.

It is an arithmetic number, because the mean of its divisors is an integer number (893520).

Almost surely, 2^6721613 is an apocalyptic number.

It is an amenable number.

6721613 is a deficient number, since it is larger than the sum of its proper divisors (426547).

6721613 is a wasteful number, since it uses less digits than its factorization.

6721613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1747.

The product of its digits is 1512, while the sum is 26.

The square root of 6721613 is about 2592.6073748256. The cubic root of 6721613 is about 188.7228564976.

Adding to 6721613 its reverse (3161276), we get a palindrome (9882889).

The spelling of 6721613 in words is "six million, seven hundred twenty-one thousand, six hundred thirteen".