91678213981440 has 180 divisors, whose sum is σ = 328041415225524. Its totient is φ = 24447523700736.

The previous prime is 91678213981439. The next prime is 91678213981451. The reversal of 91678213981440 is 4418931287619.

91678213981440 is a `hidden beast` number, since 9 + 1 + 6 + 7 + 82 + 1 + 39 + 81 + 440 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15811884205056 + 75866329776384 = 3976416^2 + 8710128^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 442017337 + ... + 442224696.

Almost surely, 2^{91678213981440} is an apocalyptic number.

91678213981440 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

91678213981440 is an abundant number, since it is smaller than the sum of its proper divisors (236363201244084).

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

91678213981440 is an equidigital number, since it uses as much as digits as its factorization.

91678213981440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884242066 (or 884242043 counting only the distinct ones).

The product of its (nonzero) digits is 20901888, while the sum is 63.

The spelling of 91678213981440 in words is "ninety-one trillion, six hundred seventy-eight billion, two hundred thirteen million, nine hundred eighty-one thousand, four hundred forty".