6420491 has 8 divisors (see below), whose sum is σ = 8004864. Its totient is φ = 5002920.

The previous prime is 6420487. The next prime is 6420511. The reversal of 6420491 is 1940246.

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 6420491 - 2² = 6420487 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6420491.

It is not an unprimeable number, because it can be changed into a prime (6420431) 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, 41615 + ... + 41768.

It is an arithmetic number, because the mean of its divisors is an integer number (1000608).

Almost surely, 2^6420491 is an apocalyptic number.

6420491 is a deficient number, since it is larger than the sum of its proper divisors (1584373).

6420491 is a wasteful number, since it uses less digits than its factorization.

6420491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83401.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 6420491 is about 2533.8687811329. The cubic root of 6420491 is about 185.8614897423.

The spelling of 6420491 in words is "six million, four hundred twenty thousand, four hundred ninety-one".