6219991 has 2 divisors, whose sum is σ = 6219992. Its totient is φ = 6219990.

The previous prime is 6219989. The next prime is 6220001. The reversal of 6219991 is 1999126.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6219991 - 2¹ = 6219989 is a prime.

Together with 6219989, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 6219991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6219901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3109995 + 3109996.

It is an arithmetic number, because the mean of its divisors is an integer number (3109996).

Almost surely, 2^6219991 is an apocalyptic number.

6219991 is a deficient number, since it is larger than the sum of its proper divisors (1).

6219991 is an equidigital number, since it uses as much as digits as its factorization.

6219991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 37.

The square root of 6219991 is about 2493.9909783317. The cubic root of 6219991 is about 183.9062908937.

The spelling of 6219991 in words is "six million, two hundred nineteen thousand, nine hundred ninety-one".