91278679440 has 240 divisors, whose sum is σ = 306927730368. Its totient is φ = 22307306496.

The previous prime is 91278679417. The next prime is 91278679487. The reversal of 91278679440 is 4497687219.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (240).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 254257981 + ... + 254258339.

Almost surely, 2^91278679440 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 91278679440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153463865184).

91278679440 is an abundant number, since it is smaller than the sum of its proper divisors (215649050928).

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

91278679440 is a wasteful number, since it uses less digits than its factorization.

91278679440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 974 (or 609 counting only the distinct ones).

The product of its (nonzero) digits is 6096384, while the sum is 57.

The spelling of 91278679440 in words is "ninety-one billion, two hundred seventy-eight million, six hundred seventy-nine thousand, four hundred forty".