91186381440 has 1152 divisors, whose sum is σ = 417285198720. Its totient is φ = 18109808640.

The previous prime is 91186381423. The next prime is 91186381453. The reversal of 91186381440 is 4418368119.

91186381440 is a `hidden beast` number, since 9 + 1 + 1 + 8 + 638 + 1 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

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

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 71406082 + ... + 71407358.

It is an arithmetic number, because the mean of its divisors is an integer number (362226735).

Almost surely, 2^91186381440 is an apocalyptic number.

91186381440 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 91186381440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208642599360).

91186381440 is an abundant number, since it is smaller than the sum of its proper divisors (326098817280).

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

91186381440 is a wasteful number, since it uses less digits than its factorization.

91186381440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350 (or 1328 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 91186381440 in words is "ninety-one billion, one hundred eighty-six million, three hundred eighty-one thousand, four hundred forty".