20681800 has 24 divisors (see below), whose sum is σ = 48085650. Its totient is φ = 8272640.

The previous prime is 20681777. The next prime is 20681813. The reversal of 20681800 is 818602.

It can be written as a sum of positive squares in 3 ways, for example, as 15007876 + 5673924 = 3874^2 + 2382^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 51505 + ... + 51904.

Almost surely, 2^20681800 is an apocalyptic number.

20681800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20681800 is an abundant number, since it is smaller than the sum of its proper divisors (27403850).

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

20681800 is a wasteful number, since it uses less digits than its factorization.

20681800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103425 (or 103416 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 20681800 is about 4547.7247058282. The cubic root of 20681800 is about 274.4918439564.

The spelling of 20681800 in words is "twenty million, six hundred eighty-one thousand, eight hundred".