20505600 has 198 divisors, whose sum is σ = 74244690. Its totient is φ = 5406720.

The previous prime is 20505599. The next prime is 20505619. The reversal of 20505600 is 650502.

It can be written as a sum of positive squares in 3 ways, for example, as 147456 + 20358144 = 384^2 + 4512^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 230356 + ... + 230444.

Almost surely, 2^20505600 is an apocalyptic number.

20505600 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 20505600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37122345).

20505600 is an abundant number, since it is smaller than the sum of its proper divisors (53739090).

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

20505600 is a wasteful number, since it uses less digits than its factorization.

20505600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 20505600 is about 4528.3109433872. The cubic root of 20505600 is about 273.7101023983.

The spelling of 20505600 in words is "twenty million, five hundred five thousand, six hundred".