21456641250 has 240 divisors, whose sum is σ = 64168584480. Its totient is φ = 5136480000.

The previous prime is 21456641159. The next prime is 21456641257. The reversal of 21456641250 is 5214665412.

21456641250 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 6 + 641 + 2 + 5 + 0 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21456641257) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 10270206 + ... + 10272294.

It is an arithmetic number, because the mean of its divisors is an integer number (267369102).

Almost surely, 2^21456641250 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21456641250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32084292240).

21456641250 is an abundant number, since it is smaller than the sum of its proper divisors (42711943230).

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

21456641250 is a wasteful number, since it uses less digits than its factorization.

21456641250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2211 (or 2193 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 21456641250 in words is "twenty-one billion, four hundred fifty-six million, six hundred forty-one thousand, two hundred fifty".