20304561816 has 768 divisors, whose sum is σ = 75841920000. Its totient is φ = 4917749760.

The previous prime is 20304561803. The next prime is 20304561821. The reversal of 20304561816 is 61816540302.

It is a happy number.

20304561816 is a `hidden beast` number, since 2 + 0 + 30 + 4 + 5 + 618 + 1 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 191 ways as a sum of consecutive naturals, for example, 228141100 + ... + 228141188.

It is an arithmetic number, because the mean of its divisors is an integer number (98752500).

Almost surely, 2^20304561816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20304561816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37920960000).

20304561816 is an abundant number, since it is smaller than the sum of its proper divisors (55537358184).

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

20304561816 is a wasteful number, since it uses less digits than its factorization.

20304561816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 20304561816 in words is "twenty billion, three hundred four million, five hundred sixty-one thousand, eight hundred sixteen".