6616991 has 2 divisors, whose sum is σ = 6616992. Its totient is φ = 6616990.

The previous prime is 6616931. The next prime is 6616993. The reversal of 6616991 is 1996166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6616991 - 2¹⁰ = 6615967 is a prime.

Together with 6616993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6616993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3308495 + 3308496.

It is an arithmetic number, because the mean of its divisors is an integer number (3308496).

Almost surely, 2^6616991 is an apocalyptic number.

6616991 is a deficient number, since it is larger than the sum of its proper divisors (1).

6616991 is an equidigital number, since it uses as much as digits as its factorization.

6616991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17496, while the sum is 38.

The square root of 6616991 is about 2572.3512590624. The cubic root of 6616991 is about 187.7385739407.

The spelling of 6616991 in words is "six million, six hundred sixteen thousand, nine hundred ninety-one".