99978278400 has 2880 divisors, whose sum is σ = 523401500160. Its totient is φ = 18048614400.

The previous prime is 99978278353. The next prime is 99978278441. The reversal of 99978278400 is 487287999.

99978278400 is a `hidden beast` number, since 9 + 99 + 78 + 2 + 78 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (2880).

It is a Harshad number since it is a multiple of its sum of digits (63).

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 287 ways as a sum of consecutive naturals, for example, 5881075192 + ... + 5881075208.

It is an arithmetic number, because the mean of its divisors is an integer number (181736632).

Almost surely, 2^99978278400 is an apocalyptic number.

99978278400 is a gapful number since it is divisible by the number (90) 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 99978278400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261700750080).

99978278400 is an abundant number, since it is smaller than the sum of its proper divisors (423423221760).

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

99978278400 is a wasteful number, since it uses less digits than its factorization.

99978278400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 18289152, while the sum is 63.

The spelling of 99978278400 in words is "ninety-nine billion, nine hundred seventy-eight million, two hundred seventy-eight thousand, four hundred".