6638400 has 126 divisors (see below), whose sum is σ = 23645622. Its totient is φ = 1766400.

The previous prime is 6638393. The next prime is 6638407. The reversal of 6638400 is 48366.

It is an interprime number because it is at equal distance from previous prime (6638393) and next prime (6638407).

It can be written as a sum of positive squares in 3 ways, for example, as 166464 + 6471936 = 408^2 + 2544^2 .

It is a super-3 number, since 3×6638400³ (a number of 21 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6638407) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 14170 + ... + 14630.

Almost surely, 2^6638400 is an apocalyptic number.

6638400 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 6638400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11822811).

6638400 is an abundant number, since it is smaller than the sum of its proper divisors (17007222).

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

6638400 is a wasteful number, since it uses less digits than its factorization.

6638400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 6638400 is about 2576.5092664301. The cubic root of 6638400 is about 187.9408294247.

The spelling of 6638400 in words is "six million, six hundred thirty-eight thousand, four hundred".