6621613 has 4 divisors (see below), whose sum is σ = 6775648. Its totient is φ = 6467580.

The previous prime is 6621607. The next prime is 6621649. The reversal of 6621613 is 3161266.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3161266 = 2 ⋅1580633.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6621613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6621413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76953 + ... + 77038.

It is an arithmetic number, because the mean of its divisors is an integer number (1693912).

Almost surely, 2^6621613 is an apocalyptic number.

It is an amenable number.

6621613 is a deficient number, since it is larger than the sum of its proper divisors (154035).

6621613 is a wasteful number, since it uses less digits than its factorization.

6621613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154034.

The product of its digits is 1296, while the sum is 25.

The square root of 6621613 is about 2573.2495020888. The cubic root of 6621613 is about 187.7822758656.

Adding to 6621613 its reverse (3161266), we get a palindrome (9782879).

The spelling of 6621613 in words is "six million, six hundred twenty-one thousand, six hundred thirteen".