21250327644 has 288 divisors, whose sum is σ = 69974195200. Its totient is φ = 5603338944.

The previous prime is 21250327633. The next prime is 21250327649. The reversal of 21250327644 is 44672305212.

21250327644 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 0 + 3 + 2 + 7 + 644 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21250327599 and 21250327608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250327649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4331697 + ... + 4336599.

Almost surely, 2^21250327644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21250327644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34987097600).

21250327644 is an abundant number, since it is smaller than the sum of its proper divisors (48723867556).

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

21250327644 is a wasteful number, since it uses less digits than its factorization.

21250327644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4956 (or 4928 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The spelling of 21250327644 in words is "twenty-one billion, two hundred fifty million, three hundred twenty-seven thousand, six hundred forty-four".