991526355456 has 640 divisors, whose sum is σ = 3365784576000. Its totient is φ = 257691893760.

The previous prime is 991526355419. The next prime is 991526355493. The reversal of 991526355456 is 654553625199.

It is an interprime number because it is at equal distance from previous prime (991526355419) and next prime (991526355493).

It is a self number, because there is not a number n which added to its sum of digits gives 991526355456.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 486279685 + ... + 486281723.

It is an arithmetic number, because the mean of its divisors is an integer number (5259038400).

Almost surely, 2^991526355456 is an apocalyptic number.

991526355456 is a gapful number since it is divisible by the number (96) 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 991526355456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1682892288000).

991526355456 is an abundant number, since it is smaller than the sum of its proper divisors (2374258220544).

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

991526355456 is a wasteful number, since it uses less digits than its factorization.

991526355456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2165 (or 2135 counting only the distinct ones).

The product of its digits is 43740000, while the sum is 60.

The spelling of 991526355456 in words is "nine hundred ninety-one billion, five hundred twenty-six million, three hundred fifty-five thousand, four hundred fifty-six".