28105006644 has 432 divisors, whose sum is σ = 91636413120. Its totient is φ = 7342876800.

The previous prime is 28105006639. The next prime is 28105006673. The reversal of 28105006644 is 44660050182.

28105006644 is a `hidden beast` number, since 2 + 8 + 1 + 0 + 5 + 0 + 0 + 6 + 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 = 28105006599 and 28105006608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 395845129 + ... + 395845199.

Almost surely, 2^28105006644 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 28105006644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45818206560).

28105006644 is an abundant number, since it is smaller than the sum of its proper divisors (63531406476).

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

28105006644 is a wasteful number, since it uses less digits than its factorization.

28105006644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 28105006644 in words is "twenty-eight billion, one hundred five million, six thousand, six hundred forty-four".