21778286400 has 1008 divisors, whose sum is σ = 91067534400. Its totient is φ = 5046312960.

The previous prime is 21778286389. The next prime is 21778286447. The reversal of 21778286400 is 468287712.

21778286400 is a `hidden beast` number, since 21 + 77 + 82 + 86 + 400 = 666.

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 polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 138715122 + ... + 138715278.

Almost surely, 2^21778286400 is an apocalyptic number.

21778286400 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 21778286400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45533767200).

21778286400 is an abundant number, since it is smaller than the sum of its proper divisors (69289248000).

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

21778286400 is a wasteful number, since it uses less digits than its factorization.

21778286400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 199 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

The spelling of 21778286400 in words is "twenty-one billion, seven hundred seventy-eight million, two hundred eighty-six thousand, four hundred".