21978243302400 has 4752 divisors, whose sum is σ = 107143357386240. Its totient is φ = 4394041344000.

The previous prime is 21978243302363. The next prime is 21978243302429. The reversal of 21978243302400 is 420334287912.

21978243302400 is a `hidden beast` number, since 2 + 1 + 9 + 78 + 2 + 4 + 330 + 240 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (4752).

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 (19) of ones.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 127041868714 + ... + 127041868886.

Almost surely, 2^{21978243302400} is an apocalyptic number.

21978243302400 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 21978243302400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53571678693120).

21978243302400 is an abundant number, since it is smaller than the sum of its proper divisors (85165114083840).

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

21978243302400 is a wasteful number, since it uses less digits than its factorization.

21978243302400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The spelling of 21978243302400 in words is "twenty-one trillion, nine hundred seventy-eight billion, two hundred forty-three million, three hundred two thousand, four hundred".