91854217728 has 1440 divisors, whose sum is σ = 368469541440. Its totient is φ = 22574039040.

The previous prime is 91854217723. The next prime is 91854217729. The reversal of 91854217728 is 82771245819.

91854217728 is a `hidden beast` number, since 9 + 1 + 8 + 542 + 1 + 77 + 28 = 666.

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

Its product of digits (2257920) is a multiple of the sum of its prime divisors (105).

It is not an unprimeable number, because it can be changed into a prime (91854217723) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1505806818 + ... + 1505806878.

It is an arithmetic number, because the mean of its divisors is an integer number (255881626).

Almost surely, 2^91854217728 is an apocalyptic number.

91854217728 is a gapful number since it is divisible by the number (98) 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 91854217728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184234770720).

91854217728 is an abundant number, since it is smaller than the sum of its proper divisors (276615323712).

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

91854217728 is a wasteful number, since it uses less digits than its factorization.

91854217728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140 (or 105 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 54.

The spelling of 91854217728 in words is "ninety-one billion, eight hundred fifty-four million, two hundred seventeen thousand, seven hundred twenty-eight".