16640000 has 120 divisors (see below), whose sum is σ = 44774730. Its totient is φ = 6144000.

The previous prime is 16639993. The next prime is 16640003. The reversal of 16640000 is 4661.

It can be written as a sum of positive squares in 5 ways, for example, as 123904 + 16516096 = 352^2 + 4064^2 .

It is not an unprimeable number, because it can be changed into a prime (16640003) 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 9 ways as a sum of consecutive naturals, for example, 1279994 + ... + 1280006.

Almost surely, 2^16640000 is an apocalyptic number.

16640000 is a gapful number since it is divisible by the number (10) 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 16640000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22387365).

16640000 is an abundant number, since it is smaller than the sum of its proper divisors (28134730).

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

16640000 is an frugal number, since it uses more digits than its factorization.

16640000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 16640000 is about 4079.2156108742. The cubic root of 16640000 is about 255.3001719544.

Adding to 16640000 its reverse (4661), we get a palindrome (16644661).

It can be divided in two parts, 16 and 640000, that multiplied together give a square (10240000 = 3200²).

The spelling of 16640000 in words is "sixteen million, six hundred forty thousand".