21878662400 has 432 divisors, whose sum is σ = 64838100096. Its totient is φ = 7153090560.

The previous prime is 21878662391. The next prime is 21878662453. The reversal of 21878662400 is 426687812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 111059102 + ... + 111059298.

Almost surely, 2^21878662400 is an apocalyptic number.

21878662400 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 21878662400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32419050048).

21878662400 is an abundant number, since it is smaller than the sum of its proper divisors (42959437696).

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

21878662400 is a wasteful number, since it uses less digits than its factorization.

21878662400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334 (or 315 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 44.

The spelling of 21878662400 in words is "twenty-one billion, eight hundred seventy-eight million, six hundred sixty-two thousand, four hundred".