20388317544 has 160 divisors (see below), whose sum is σ = 65328151680. Its totient is φ = 5819527296.

The previous prime is 20388317539. The next prime is 20388317567. The reversal of 20388317544 is 44571388302.

20388317544 is a `hidden beast` number, since 20 + 3 + 8 + 83 + 1 + 7 + 544 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 20388317544.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 7287954 + ... + 7290750.

It is an arithmetic number, because the mean of its divisors is an integer number (408300948).

Almost surely, 2^20388317544 is an apocalyptic number.

20388317544 is a gapful number since it is divisible by the number (24) 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 20388317544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32664075840).

20388317544 is an abundant number, since it is smaller than the sum of its proper divisors (44939834136).

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

20388317544 is a wasteful number, since it uses less digits than its factorization.

20388317544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4429 (or 4416 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The spelling of 20388317544 in words is "twenty billion, three hundred eighty-eight million, three hundred seventeen thousand, five hundred forty-four".