20404800 has 252 divisors, whose sum is σ = 78818740. Its totient is φ = 4976640.

The previous prime is 20404771. The next prime is 20404801. The reversal of 20404800 is 840402.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1115136 + 19289664 = 1056^2 + 4392^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20404801) 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 35 ways as a sum of consecutive naturals, for example, 187146 + ... + 187254.

Almost surely, 2^20404800 is an apocalyptic number.

20404800 is a gapful number since it is divisible by the number (20) 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 20404800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39409370).

20404800 is an abundant number, since it is smaller than the sum of its proper divisors (58413940).

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

20404800 is a wasteful number, since it uses less digits than its factorization.

20404800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 20404800 is about 4517.1672539325. The cubic root of 20404800 is about 273.2608704733.

The spelling of 20404800 in words is "twenty million, four hundred four thousand, eight hundred".