20509318368 has 384 divisors, whose sum is σ = 75116160000. Its totient is φ = 5288785920.

The previous prime is 20509318309. The next prime is 20509318387. The reversal of 20509318368 is 86381390502.

It is a happy number.

20509318368 is a `hidden beast` number, since 2 + 0 + 509 + 3 + 1 + 83 + 68 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 9911638 + ... + 9913706.

It is an arithmetic number, because the mean of its divisors is an integer number (195615000).

Almost surely, 2^20509318368 is an apocalyptic number.

20509318368 is a gapful number since it is divisible by the number (28) 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 20509318368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37558080000).

20509318368 is an abundant number, since it is smaller than the sum of its proper divisors (54606841632).

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

20509318368 is a wasteful number, since it uses less digits than its factorization.

20509318368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255 (or 2241 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 20509318368 in words is "twenty billion, five hundred nine million, three hundred eighteen thousand, three hundred sixty-eight".