20505124040 has 16 divisors (see below), whose sum is σ = 46136529180. Its totient is φ = 8202049600.

The previous prime is 20505124033. The next prime is 20505124069. The reversal of 20505124040 is 4042150502.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16976526436 + 3528597604 = 130294^2 + 59402^2 .

It is a super-2 number, since 2×20505124040² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20505123997 and 20505124015.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256314011 + ... + 256314090.

Almost surely, 2^20505124040 is an apocalyptic number.

20505124040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20505124040 is an abundant number, since it is smaller than the sum of its proper divisors (25631405140).

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

20505124040 is a wasteful number, since it uses less digits than its factorization.

20505124040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512628112 (or 512628108 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

Adding to 20505124040 its reverse (4042150502), we get a palindrome (24547274542).

The spelling of 20505124040 in words is "twenty billion, five hundred five million, one hundred twenty-four thousand, forty".