20005120 has 36 divisors (see below), whose sum is σ = 47921580. Its totient is φ = 8001536.

The previous prime is 20005093. The next prime is 20005129. The reversal of 20005120 is 2150002.

It can be written as a sum of positive squares in 2 ways, for example, as 15745024 + 4260096 = 3968^2 + 2064^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 20005097 and 20005106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20005129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6535 + ... + 9094.

It is an arithmetic number, because the mean of its divisors is an integer number (1331155).

Almost surely, 2^20005120 is an apocalyptic number.

20005120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20005120 is an abundant number, since it is smaller than the sum of its proper divisors (27916460).

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

20005120 is an equidigital number, since it uses as much as digits as its factorization.

20005120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15650 (or 15636 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 20005120 is about 4472.7083517708. The cubic root of 20005120 is about 271.4649227135.

Adding to 20005120 its reverse (2150002), we get a palindrome (22155122).

It can be divided in two parts, 2000 and 5120, that multiplied together give a square (10240000 = 3200²).

The spelling of 20005120 in words is "twenty million, five thousand, one hundred twenty".