99511991040 has 432 divisors, whose sum is σ = 403322734080. Its totient is φ = 20677386240.

The previous prime is 99511991039. The next prime is 99511991041. The reversal of 99511991040 is 4019911599.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (99511991039) and next prime (99511991041).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99511991041) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2045721 + ... + 2093799.

It is an arithmetic number, because the mean of its divisors is an integer number (933617440).

Almost surely, 2^99511991040 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 99511991040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (201661367040).

99511991040 is an abundant number, since it is smaller than the sum of its proper divisors (303810743040).

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

99511991040 is a wasteful number, since it uses less digits than its factorization.

99511991040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48128 (or 48107 counting only the distinct ones).

The product of its (nonzero) digits is 131220, while the sum is 48.

The spelling of 99511991040 in words is "ninety-nine billion, five hundred eleven million, nine hundred ninety-one thousand, forty".