20724865920 has 768 divisors, whose sum is σ = 84137564160. Its totient is φ = 4644864000.

The previous prime is 20724865913. The next prime is 20724865957. The reversal of 20724865920 is 2956842702.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 76475385 + ... + 76475655.

It is an arithmetic number, because the mean of its divisors is an integer number (109554120).

Almost surely, 2^20724865920 is an apocalyptic number.

20724865920 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 20724865920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42068782080).

20724865920 is an abundant number, since it is smaller than the sum of its proper divisors (63412698240).

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

20724865920 is a wasteful number, since it uses less digits than its factorization.

20724865920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395 (or 380 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 20724865920 in words is "twenty billion, seven hundred twenty-four million, eight hundred sixty-five thousand, nine hundred twenty".