6619991 has 8 divisors (see below), whose sum is σ = 7617024. Its totient is φ = 5635800.

The previous prime is 6619981. The next prime is 6620011. The reversal of 6619991 is 1999166.

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 6619991 - 2⁶ = 6619927 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 (6619931) 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 7 ways as a sum of consecutive naturals, for example, 2075 + ... + 4188.

It is an arithmetic number, because the mean of its divisors is an integer number (952128).

Almost surely, 2^6619991 is an apocalyptic number.

6619991 is a deficient number, since it is larger than the sum of its proper divisors (997033).

6619991 is a wasteful number, since it uses less digits than its factorization.

6619991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6421.

The product of its digits is 26244, while the sum is 41.

The square root of 6619991 is about 2572.9343170785. The cubic root of 6619991 is about 187.7669418513.

The spelling of 6619991 in words is "six million, six hundred nineteen thousand, nine hundred ninety-one".