6440900 has 36 divisors (see below), whose sum is σ = 14465220. Its totient is φ = 2486400.

The previous prime is 6440893. The next prime is 6440933. The reversal of 6440900 is 90446.

It can be written as a sum of positive squares in 6 ways, for example, as 9604 + 6431296 = 98^2 + 2536^2 .

It is an Ulam number.

It is a plaindrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1790 + ... + 4010.

Almost surely, 2^6440900 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6440900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7232610).

6440900 is an abundant number, since it is smaller than the sum of its proper divisors (8024320).

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

6440900 is a wasteful number, since it uses less digits than its factorization.

6440900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2264 (or 2257 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 6440900 is about 2537.8928267364. The cubic root of 6440900 is about 186.0582158698.

The spelling of 6440900 in words is "six million, four hundred forty thousand, nine hundred".