6445820 has 24 divisors (see below), whose sum is σ = 13674528. Its totient is φ = 2552000.

The previous prime is 6445811. The next prime is 6445823. The reversal of 6445820 is 285446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6445823) 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 in 7 ways as a sum of consecutive naturals, for example, 425 + ... + 3615.

It is an arithmetic number, because the mean of its divisors is an integer number (569772).

Almost surely, 2^6445820 is an apocalyptic number.

It is an amenable number.

6445820 is an abundant number, since it is smaller than the sum of its proper divisors (7228708).

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

6445820 is a wasteful number, since it uses less digits than its factorization.

6445820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3301 (or 3299 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 6445820 is about 2538.8619497720. The cubic root of 6445820 is about 186.1055784763.

The spelling of 6445820 in words is "six million, four hundred forty-five thousand, eight hundred twenty".