20721254400 has 1080 divisors, whose sum is σ = 93809037504. Its totient is φ = 4246732800.

The previous prime is 20721254357. The next prime is 20721254417. The reversal of 20721254400 is 445212702.

20721254400 is a `hidden beast` number, since 2 + 0 + 7 + 2 + 1 + 254 + 400 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 283852764 + ... + 283852836.

Almost surely, 2^20721254400 is an apocalyptic number.

20721254400 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 20721254400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46904518752).

20721254400 is an abundant number, since it is smaller than the sum of its proper divisors (73087783104).

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

20721254400 is a wasteful number, since it uses less digits than its factorization.

20721254400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 27.

The spelling of 20721254400 in words is "twenty billion, seven hundred twenty-one million, two hundred fifty-four thousand, four hundred".