28165571216640 has 3024 divisors, whose sum is σ = 123798008087040. Its totient is φ = 6089615769600.

The previous prime is 28165571216639. The next prime is 28165571216647. The reversal of 28165571216640 is 4661217556182.

28165571216640 is a `hidden beast` number, since 2 + 8 + 1 + 6 + 5 + 571 + 2 + 1 + 6 + 64 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28165571216647) by changing a digit.

It is a polite number, since it can be written in 335 ways as a sum of consecutive naturals, for example, 45501730251 + ... + 45501730869.

Almost surely, 2^{28165571216640} is an apocalyptic number.

28165571216640 is a gapful number since it is divisible by the number (20) 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 28165571216640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61899004043520).

28165571216640 is an abundant number, since it is smaller than the sum of its proper divisors (95632436870400).

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

28165571216640 is a wasteful number, since it uses less digits than its factorization.

28165571216640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 724 (or 684 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 54.

The spelling of 28165571216640 in words is "twenty-eight trillion, one hundred sixty-five billion, five hundred seventy-one million, two hundred sixteen thousand, six hundred forty".