20004124520 has 16 divisors (see below), whose sum is σ = 45009280260. Its totient is φ = 8001649792.

The previous prime is 20004124507. The next prime is 20004124523. The reversal of 20004124520 is 2542140002.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18089712004 + 1914412516 = 134498^2 + 43754^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 20004124492 and 20004124501.

It is not an unprimeable number, because it can be changed into a prime (20004124523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 250051517 + ... + 250051596.

Almost surely, 2^20004124520 is an apocalyptic number.

20004124520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20004124520 is an abundant number, since it is smaller than the sum of its proper divisors (25005155740).

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

20004124520 is a wasteful number, since it uses less digits than its factorization.

20004124520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500103124 (or 500103120 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

Adding to 20004124520 its reverse (2542140002), we get a palindrome (22546264522).

The spelling of 20004124520 in words is "twenty billion, four million, one hundred twenty-four thousand, five hundred twenty".