20513232240 has 160 divisors (see below), whose sum is σ = 67403114496. Its totient is φ = 5142958080.

The previous prime is 20513232191. The next prime is 20513232247. The reversal of 20513232240 is 4223231502.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20513232240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513232247) 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 31 ways as a sum of consecutive naturals, for example, 4987785 + ... + 4991895.

Almost surely, 2^20513232240 is an apocalyptic number.

20513232240 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 20513232240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33701557248).

20513232240 is an abundant number, since it is smaller than the sum of its proper divisors (46889882256).

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

20513232240 is a wasteful number, since it uses less digits than its factorization.

20513232240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5367 (or 5361 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 24.

Adding to 20513232240 its reverse (4223231502), we get a palindrome (24736463742).

The spelling of 20513232240 in words is "twenty billion, five hundred thirteen million, two hundred thirty-two thousand, two hundred forty".