20178815904 has 240 divisors, whose sum is σ = 64136080008. Its totient is φ = 6186958848.

The previous prime is 20178815897. The next prime is 20178815933. The reversal of 20178815904 is 40951887102.

It can be written as a sum of positive squares in 4 ways, for example, as 11718495504 + 8460320400 = 108252^2 + 91980^2 .

It is a super-2 number, since 2×20178815904² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20178815904.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11354664 + ... + 11356440.

Almost surely, 2^20178815904 is an apocalyptic number.

20178815904 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 20178815904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32068040004).

20178815904 is an abundant number, since it is smaller than the sum of its proper divisors (43957264104).

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

20178815904 is a wasteful number, since it uses less digits than its factorization.

20178815904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2149 (or 2132 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 20178815904 in words is "twenty billion, one hundred seventy-eight million, eight hundred fifteen thousand, nine hundred four".