99991015840 has 96 divisors (see below), whose sum is σ = 246590023680. Its totient is φ = 38271129600.

The previous prime is 99991015799. The next prime is 99991015877. The reversal of 99991015840 is 4851019999.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 328185 + ... + 554695.

It is an arithmetic number, because the mean of its divisors is an integer number (2568646080).

Almost surely, 2^99991015840 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 99991015840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123295011840).

99991015840 is an abundant number, since it is smaller than the sum of its proper divisors (146599007840).

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

99991015840 is a wasteful number, since it uses less digits than its factorization.

99991015840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226646 (or 226638 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 55.

The spelling of 99991015840 in words is "ninety-nine billion, nine hundred ninety-one million, fifteen thousand, eight hundred forty".