21398531788800 has 2496 divisors, whose sum is σ = 86351016038400. Its totient is φ = 5241476874240.

The previous prime is 21398531788793. The next prime is 21398531788807. The reversal of 21398531788800 is 888713589312.

21398531788800 is a `hidden beast` number, since 2 + 1 + 3 + 98 + 531 + 7 + 8 + 8 + 8 + 0 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21398531788793) and next prime (21398531788807).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21398531788807) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 199986278347 + ... + 199986278453.

Almost surely, 2^{21398531788800} is an apocalyptic number.

21398531788800 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 21398531788800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43175508019200).

21398531788800 is an abundant number, since it is smaller than the sum of its proper divisors (64952484249600).

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

21398531788800 is an equidigital number, since it uses as much as digits as its factorization.

21398531788800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 23224320, while the sum is 63.

The spelling of 21398531788800 in words is "twenty-one trillion, three hundred ninety-eight billion, five hundred thirty-one million, seven hundred eighty-eight thousand, eight hundred".