91510597440 has 336 divisors, whose sum is σ = 337034215440. Its totient is φ = 22708224000.

The previous prime is 91510597439. The next prime is 91510597463. The reversal of 91510597440 is 4479501519.

91510597440 is a `hidden beast` number, since 9 + 1 + 5 + 10 + 597 + 4 + 40 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 5187456576 + 86323140864 = 72024^2 + 293808^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4346940 + ... + 4367940.

Almost surely, 2^91510597440 is an apocalyptic number.

91510597440 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 91510597440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168517107720).

91510597440 is an abundant number, since it is smaller than the sum of its proper divisors (245523618000).

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

91510597440 is a wasteful number, since it uses less digits than its factorization.

91510597440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21130 (or 21117 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 45.

The spelling of 91510597440 in words is "ninety-one billion, five hundred ten million, five hundred ninety-seven thousand, four hundred forty".