20644723400 has 192 divisors, whose sum is σ = 56273481600. Its totient is φ = 6897623040.

The previous prime is 20644723397. The next prime is 20644723441. The reversal of 20644723400 is 432744602.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 9097466 + ... + 9099734.

It is an arithmetic number, because the mean of its divisors is an integer number (293091050).

Almost surely, 2^20644723400 is an apocalyptic number.

20644723400 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 20644723400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28136740800).

20644723400 is an abundant number, since it is smaller than the sum of its proper divisors (35628758200).

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

20644723400 is a wasteful number, since it uses less digits than its factorization.

20644723400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2456 (or 2447 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 32.

The spelling of 20644723400 in words is "twenty billion, six hundred forty-four million, seven hundred twenty-three thousand, four hundred".