99999561424 has 120 divisors (see below), whose sum is σ = 233074368000. Its totient is φ = 41399205120.

The previous prime is 99999561379. The next prime is 99999561433. The reversal of 99999561424 is 42416599999.

It is a super-3 number, since 3×99999561424³ (a number of 34 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 99999561424.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14554662 + ... + 14561530.

It is an arithmetic number, because the mean of its divisors is an integer number (1942286400).

Almost surely, 2^99999561424 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 99999561424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116537184000).

99999561424 is an abundant number, since it is smaller than the sum of its proper divisors (133074806576).

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

99999561424 is a wasteful number, since it uses less digits than its factorization.

99999561424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7521 (or 7508 counting only the distinct ones).

The product of its digits is 56687040, while the sum is 67.

The spelling of 99999561424 in words is "ninety-nine billion, nine hundred ninety-nine million, five hundred sixty-one thousand, four hundred twenty-four".