20938478400 has 672 divisors, whose sum is σ = 92386586880. Its totient is φ = 4503306240.

The previous prime is 20938478387. The next prime is 20938478423. The reversal of 20938478400 is 487483902.

20938478400 is a `hidden beast` number, since 209 + 38 + 4 + 7 + 8 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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 95 ways as a sum of consecutive naturals, for example, 5138764 + ... + 5142836.

It is an arithmetic number, because the mean of its divisors is an integer number (137480040).

Almost surely, 2^20938478400 is an apocalyptic number.

20938478400 is a gapful number since it is divisible by the number (20) 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 20938478400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46193293440).

20938478400 is an abundant number, since it is smaller than the sum of its proper divisors (71448108480).

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

20938478400 is a wasteful number, since it uses less digits than its factorization.

20938478400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4128 (or 4107 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 20938478400 in words is "twenty billion, nine hundred thirty-eight million, four hundred seventy-eight thousand, four hundred".