20481638400 has 408 divisors, whose sum is σ = 75413010560. Its totient is φ = 5449973760.

The previous prime is 20481638377. The next prime is 20481638413. The reversal of 20481638400 is 483618402.

20481638400 is a `hidden beast` number, since 204 + 8 + 16 + 38 + 400 = 666.

It is a super-3 number, since 3×20481638400³ (a number of 32 digits) contains 333 as substring.

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 polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44236569 + ... + 44237031.

Almost surely, 2^20481638400 is an apocalyptic number.

20481638400 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 20481638400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37706505280).

20481638400 is an abundant number, since it is smaller than the sum of its proper divisors (54931372160).

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

20481638400 is an frugal number, since it uses more digits than its factorization.

20481638400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514 (or 473 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The spelling of 20481638400 in words is "twenty billion, four hundred eighty-one million, six hundred thirty-eight thousand, four hundred".