20505103240 has 96 divisors (see below), whose sum is σ = 48813598080. Its totient is φ = 7751044224.

The previous prime is 20505103219. The next prime is 20505103243. The reversal of 20505103240 is 4230150502.

It is not an unprimeable number, because it can be changed into a prime (20505103243) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6684187 + ... + 6687253.

It is an arithmetic number, because the mean of its divisors is an integer number (508474980).

Almost surely, 2^20505103240 is an apocalyptic number.

20505103240 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 20505103240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24406799040).

20505103240 is an abundant number, since it is smaller than the sum of its proper divisors (28308494840).

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

20505103240 is a wasteful number, since it uses less digits than its factorization.

20505103240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3579 (or 3556 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

Adding to 20505103240 its reverse (4230150502), we get a palindrome (24735253742).

The spelling of 20505103240 in words is "twenty billion, five hundred five million, one hundred three thousand, two hundred forty".