91727432640 has 280 divisors, whose sum is σ = 336819069312. Its totient is φ = 23671388160.

The previous prime is 91727432633. The next prime is 91727432663. The reversal of 91727432640 is 4623472719.

91727432640 is a `hidden beast` number, since 9 + 17 + 274 + 326 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 746442 + ... + 860598.

Almost surely, 2^91727432640 is an apocalyptic number.

91727432640 is a gapful number since it is divisible by the number (90) 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 91727432640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168409534656).

91727432640 is an abundant number, since it is smaller than the sum of its proper divisors (245091636672).

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

91727432640 is a wasteful number, since it uses less digits than its factorization.

91727432640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114217 (or 114198 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The spelling of 91727432640 in words is "ninety-one billion, seven hundred twenty-seven million, four hundred thirty-two thousand, six hundred forty".