1600 has 21 divisors (see below), whose sum is σ = 3937. Its totient is φ = 640.

The previous prime is 1597. The next prime is 1601. The reversal of 1600 is 61.

1600 = T₃₉ + T₄₀.

The square root of 1600 is 40.

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

1600 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in only one way, i.e., 576 + 1024 = 24^2 + 32^2 .

It is a hoax number, since the sum of its digits (7) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

1600 is a nontrivial repdigit in base 7.

It is a plaindrome in base 6, base 7 and base 11.

It is a nialpdrome in base 7, base 8, base 13 and base 16.

It is a zygodrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (1601) by changing a digit.

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, 318 + ... + 322.

1600 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1600 is the 40-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1600

1600 is an abundant number, since it is smaller than the sum of its proper divisors (2337).

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

1600 is an equidigital number, since it uses as much as digits as its factorization.

1600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22 (or 7 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 7.

The cubic root of 1600 is about 11.6960709529.

Adding to 1600 its reverse (61), we get a palindrome (1661).

The spelling of 1600 in words is "one thousand, six hundred".