20121800 has 24 divisors (see below), whose sum is σ = 46783650. Its totient is φ = 8048640.

The previous prime is 20121799. The next prime is 20121811. The reversal of 20121800 is 812102.

It can be written as a sum of positive squares in 3 ways, for example, as 15952036 + 4169764 = 3994^2 + 2042^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 50105 + ... + 50504.

Almost surely, 2^20121800 is an apocalyptic number.

20121800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121800 is an abundant number, since it is smaller than the sum of its proper divisors (26661850).

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

20121800 is a wasteful number, since it uses less digits than its factorization.

20121800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100625 (or 100616 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 20121800 is about 4485.7329389967. The cubic root of 20121800 is about 271.9916736206.

Adding to 20121800 its reverse (812102), we get a palindrome (20933902).

The spelling of 20121800 in words is "twenty million, one hundred twenty-one thousand, eight hundred".