28165997664 has 576 divisors, whose sum is σ = 100085207040. Its totient is φ = 7332249600.

The previous prime is 28165997641. The next prime is 28165997719. The reversal of 28165997664 is 46679956182.

28165997664 is a `hidden beast` number, since 28 + 16 + 599 + 7 + 6 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 273456237 + ... + 273456339.

It is an arithmetic number, because the mean of its divisors is an integer number (173759040).

Almost surely, 2^28165997664 is an apocalyptic number.

28165997664 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 28165997664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50042603520).

28165997664 is an abundant number, since it is smaller than the sum of its proper divisors (71919209376).

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

28165997664 is a wasteful number, since it uses less digits than its factorization.

28165997664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 312 counting only the distinct ones).

The product of its digits is 39191040, while the sum is 63.

The spelling of 28165997664 in words is "twenty-eight billion, one hundred sixty-five million, nine hundred ninety-seven thousand, six hundred sixty-four".