6400620 has 84 divisors (see below), whose sum is σ = 20198640. Its totient is φ = 1702944.

The previous prime is 6400607. The next prime is 6400621. The reversal of 6400620 is 260046.

6400620 is a `hidden beast` number, since 6 + 40 + 0 + 620 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 6400593 and 6400602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6400621) by changing a digit.

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 27 ways as a sum of consecutive naturals, for example, 14361 + ... + 14799.

It is an arithmetic number, because the mean of its divisors is an integer number (240460).

Almost surely, 2^6400620 is an apocalyptic number.

6400620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6400620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10099320).

6400620 is an abundant number, since it is smaller than the sum of its proper divisors (13798020).

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

6400620 is a wasteful number, since it uses less digits than its factorization.

6400620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466 (or 449 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 6400620 is about 2529.9446634265. The cubic root of 6400620 is about 185.6695485365.

Adding to 6400620 its reverse (260046), we get a palindrome (6660666).

The spelling of 6400620 in words is "six million, four hundred thousand, six hundred twenty".