1638400 has 51 divisors (see below), whose sum is σ = 4063201. Its totient is φ = 655360.

The previous prime is 1638353. The next prime is 1638431. The reversal of 1638400 is 48361.

The square root of 1638400 is 1280.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 589824 + 1048576 = 768^2 + 1024^2 .

It is a super-3 number, since 3×1638400³ = 13194139533312000000, which contains 333 as substring.

It is a Duffinian number.

It is a nialpdrome in base 8.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 327678 + ... + 327682.

2^1638400 is an apocalyptic number.

1638400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1638400 is the 1280-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638400

1638400 is an abundant number, since it is smaller than the sum of its proper divisors (2424801).

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

1638400 is an frugal number, since it uses more digits than its factorization.

1638400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42 (or 7 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The cubic root of 1638400 is about 117.8890079565.

Multiplying 1638400 by its product of nonzero digits (576), we get a square (943718400 = 30720²).

It can be divided in two parts, 16 and 38400, that added together give a 4-th power (38416 = 14⁴).

The spelling of 1638400 in words is "one million, six hundred thirty-eight thousand, four hundred".