6420505 has 32 divisors (see below), whose sum is σ = 9644544. Its totient is φ = 3995136.

The previous prime is 6420487. The next prime is 6420511. The reversal of 6420505 is 5050246.

It is a cyclic number.

It is not a de Polignac number, because 6420505 - 2⁷ = 6420377 is a prime.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 46797 + ... + 46933.

It is an arithmetic number, because the mean of its divisors is an integer number (301392).

Almost surely, 2^6420505 is an apocalyptic number.

6420505 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6420505 is a deficient number, since it is larger than the sum of its proper divisors (3224039).

6420505 is a wasteful number, since it uses less digits than its factorization.

6420505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 6420505 is about 2533.8715437054. The cubic root of 6420505 is about 185.8616248337.

The spelling of 6420505 in words is "six million, four hundred twenty thousand, five hundred five".