6405820 has 12 divisors (see below), whose sum is σ = 13452264. Its totient is φ = 2562320.

The previous prime is 6405811. The next prime is 6405827. The reversal of 6405820 is 285046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6405827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160126 + ... + 160165.

It is an arithmetic number, because the mean of its divisors is an integer number (1121022).

Almost surely, 2^6405820 is an apocalyptic number.

It is an amenable number.

6405820 is an abundant number, since it is smaller than the sum of its proper divisors (7046444).

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

6405820 is a wasteful number, since it uses less digits than its factorization.

6405820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320300 (or 320298 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 6405820 is about 2530.9721452438. The cubic root of 6405820 is about 185.7198155581.

It can be divided in two parts, 6405 and 820, that added together give a square (7225 = 85²).

The spelling of 6405820 in words is "six million, four hundred five thousand, eight hundred twenty".