91780138582 has 72 divisors (see below), whose sum is σ = 159060539232. Its totient is φ = 39642023520.

The previous prime is 91780138579. The next prime is 91780138589. The reversal of 91780138582 is 28583108719.

It is a happy number.

It is a super-2 number, since 2×91780138582² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91780138589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 196531113 + ... + 196531579.

It is an arithmetic number, because the mean of its divisors is an integer number (2209174156).

Almost surely, 2^91780138582 is an apocalyptic number.

91780138582 is a deficient number, since it is larger than the sum of its proper divisors (67280400650).

91780138582 is a wasteful number, since it uses less digits than its factorization.

91780138582 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1042 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 52.

The spelling of 91780138582 in words is "ninety-one billion, seven hundred eighty million, one hundred thirty-eight thousand, five hundred eighty-two".