91971587328 has 36 divisors (see below), whose sum is σ = 244778549568. Its totient is φ = 30657195520.

The previous prime is 91971587291. The next prime is 91971587333. The reversal of 91971587328 is 82378517919.

It is a super-3 number, since 3×91971587328³ (a number of 34 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors.

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 3 ways as a sum of consecutive naturals, for example, 59876568 + ... + 59878103.

Almost surely, 2^91971587328 is an apocalyptic number.

It is an amenable number.

91971587328 is an abundant number, since it is smaller than the sum of its proper divisors (152806962240).

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

91971587328 is a wasteful number, since it uses less digits than its factorization.

91971587328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119754690 (or 119754676 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 60.

The spelling of 91971587328 in words is "ninety-one billion, nine hundred seventy-one million, five hundred eighty-seven thousand, three hundred twenty-eight".