91278215591976 has 384 divisors, whose sum is σ = 320228857728000. Its totient is φ = 22859409033216.

The previous prime is 91278215591929. The next prime is 91278215592001. The reversal of 91278215591976 is 67919551287219.

91278215591976 is a `hidden beast` number, since 9 + 1 + 2 + 7 + 8 + 21 + 5 + 591 + 9 + 7 + 6 = 666.

It is a super-2 number, since 2×91278215591976² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4852995 + ... + 14356461.

It is an arithmetic number, because the mean of its divisors is an integer number (833929317000).

Almost surely, 2^{91278215591976} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91278215591976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160114428864000).

91278215591976 is an abundant number, since it is smaller than the sum of its proper divisors (228950642136024).

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

91278215591976 is a wasteful number, since it uses less digits than its factorization.

91278215591976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9503581 (or 9503574 counting only the distinct ones).

The product of its digits is 171460800, while the sum is 72.

The spelling of 91278215591976 in words is "ninety-one trillion, two hundred seventy-eight billion, two hundred fifteen million, five hundred ninety-one thousand, nine hundred seventy-six".