28356257664 has 288 divisors, whose sum is σ = 99051722640. Its totient is φ = 7749181440.

The previous prime is 28356257651. The next prime is 28356257707. The reversal of 28356257664 is 46675265382.

28356257664 is a `hidden beast` number, since 2 + 8 + 3 + 5 + 6 + 2 + 576 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a self number, because there is not a number n which added to its sum of digits gives 28356257664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1287384 + ... + 1309224.

Almost surely, 2^28356257664 is an apocalyptic number.

28356257664 is a gapful number since it is divisible by the number (24) 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 28356257664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49525861320).

28356257664 is an abundant number, since it is smaller than the sum of its proper divisors (70695464976).

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

28356257664 is a wasteful number, since it uses less digits than its factorization.

28356257664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21898 (or 21876 counting only the distinct ones).

The product of its digits is 14515200, while the sum is 54.

The spelling of 28356257664 in words is "twenty-eight billion, three hundred fifty-six million, two hundred fifty-seven thousand, six hundred sixty-four".