20836638720 has 448 divisors, whose sum is σ = 75304131840. Its totient is φ = 5465309184.

The previous prime is 20836638679. The next prime is 20836638749. The reversal of 20836638720 is 2783663802.

20836638720 is a `hidden beast` number, since 2 + 0 + 8 + 3 + 6 + 638 + 7 + 2 + 0 = 666.

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 31 ways as a sum of consecutive naturals, for example, 91791247 + ... + 91791473.

It is an arithmetic number, because the mean of its divisors is an integer number (168089580).

Almost surely, 2^20836638720 is an apocalyptic number.

20836638720 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 20836638720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37652065920).

20836638720 is an abundant number, since it is smaller than the sum of its proper divisors (54467493120).

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

20836638720 is an equidigital number, since it uses as much as digits as its factorization.

20836638720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350 (or 320 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The spelling of 20836638720 in words is "twenty billion, eight hundred thirty-six million, six hundred thirty-eight thousand, seven hundred twenty".