99721842 has 64 divisors (see below), whose sum is σ = 230653440. Its totient is φ = 28425600.

The previous prime is 99721841. The next prime is 99721877. The reversal of 99721842 is 24812799.

It is a junction number, because it is equal to n+sod(n) for n = 99721794 and 99721803.

It is not an unprimeable number, because it can be changed into a prime (99721841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 352233 + ... + 352515.

It is an arithmetic number, because the mean of its divisors is an integer number (3603960).

Almost surely, 2^99721842 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99721842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115326720).

99721842 is an abundant number, since it is smaller than the sum of its proper divisors (130931598).

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

99721842 is a wasteful number, since it uses less digits than its factorization.

99721842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599.

The product of its digits is 72576, while the sum is 42.

The square root of 99721842 is about 9986.0824150414. The cubic root of 99721842 is about 463.7281186897.

The spelling of 99721842 in words is "ninety-nine million, seven hundred twenty-one thousand, eight hundred forty-two".