20721747110400 has 1200 divisors, whose sum is σ = 90018863590656. Its totient is φ = 4608328826880.

The previous prime is 20721747110359. The next prime is 20721747110423. The reversal of 20721747110400 is 401174712702.

It is a happy number.

20721747110400 is a `hidden beast` number, since 2 + 0 + 7 + 2 + 174 + 71 + 10 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (1200).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 268492617 + ... + 268569783.

Almost surely, 2^{20721747110400} is an apocalyptic number.

20721747110400 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 20721747110400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45009431795328).

20721747110400 is an abundant number, since it is smaller than the sum of its proper divisors (69297116480256).

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

20721747110400 is an equidigital number, since it uses as much as digits as its factorization.

20721747110400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77251 (or 77221 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The spelling of 20721747110400 in words is "twenty trillion, seven hundred twenty-one billion, seven hundred forty-seven million, one hundred ten thousand, four hundred".