6420787 has 2 divisors, whose sum is σ = 6420788. Its totient is φ = 6420786.

The previous prime is 6420769. The next prime is 6420809. The reversal of 6420787 is 7870246.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6420787 is a prime.

6420787 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6420707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3210393 + 3210394.

It is an arithmetic number, because the mean of its divisors is an integer number (3210394).

Almost surely, 2^6420787 is an apocalyptic number.

6420787 is a deficient number, since it is larger than the sum of its proper divisors (1).

6420787 is an equidigital number, since it uses as much as digits as its factorization.

6420787 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 34.

The square root of 6420787 is about 2533.9271891670. The cubic root of 6420787 is about 185.8643459183.

The spelling of 6420787 in words is "six million, four hundred twenty thousand, seven hundred eighty-seven".