20724624440 has 128 divisors (see below), whose sum is σ = 50816747520. Its totient is φ = 7561382400.

The previous prime is 20724624407. The next prime is 20724624443. The reversal of 20724624440 is 4442642702.

It is a self number, because there is not a number n which added to its sum of digits gives 20724624440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20724624443) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20912345 + ... + 20913335.

It is an arithmetic number, because the mean of its divisors is an integer number (397005840).

Almost surely, 2^20724624440 is an apocalyptic number.

20724624440 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 20724624440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25408373760).

20724624440 is an abundant number, since it is smaller than the sum of its proper divisors (30092123080).

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

20724624440 is a wasteful number, since it uses less digits than its factorization.

20724624440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1453 (or 1449 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 35.

The spelling of 20724624440 in words is "twenty billion, seven hundred twenty-four million, six hundred twenty-four thousand, four hundred forty".