6390820 has 12 divisors (see below), whose sum is σ = 13420764. Its totient is φ = 2556320.

The previous prime is 6390799. The next prime is 6390829. The reversal of 6390820 is 280936.

It can be written as a sum of positive squares in 2 ways, for example, as 2286144 + 4104676 = 1512^2 + 2026^2 .

It is not an unprimeable number, because it can be changed into a prime (6390829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159751 + ... + 159790.

It is an arithmetic number, because the mean of its divisors is an integer number (1118397).

Almost surely, 2^6390820 is an apocalyptic number.

It is an amenable number.

6390820 is an abundant number, since it is smaller than the sum of its proper divisors (7029944).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6390820 is a wasteful number, since it uses less digits than its factorization.

6390820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319550 (or 319548 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 6390820 is about 2528.0071202431. The cubic root of 6390820 is about 185.5747404809.

The spelling of 6390820 in words is "six million, three hundred ninety thousand, eight hundred twenty".