20818473984 has 792 divisors, whose sum is σ = 79453731840. Its totient is φ = 5364817920.

The previous prime is 20818473967. The next prime is 20818474003. The reversal of 20818473984 is 48937481802.

It is a happy number.

20818473984 is a `hidden beast` number, since 2 + 0 + 81 + 8 + 473 + 98 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (792).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 20818473984.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 163924929 + ... + 163925055.

Almost surely, 2^20818473984 is an apocalyptic number.

20818473984 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 20818473984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39726865920).

20818473984 is an abundant number, since it is smaller than the sum of its proper divisors (58635257856).

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

20818473984 is a wasteful number, since it uses less digits than its factorization.

20818473984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The spelling of 20818473984 in words is "twenty billion, eight hundred eighteen million, four hundred seventy-three thousand, nine hundred eighty-four".