79821100 has 72 divisors (see below), whose sum is σ = 179363520. Its totient is φ = 30818880.

The previous prime is 79821097. The next prime is 79821101. The reversal of 79821100 is 112897.

It is not an unprimeable number, because it can be changed into a prime (79821101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 489619 + ... + 489781.

It is an arithmetic number, because the mean of its divisors is an integer number (2491160).

Almost surely, 2^79821100 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 79821100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89681760).

79821100 is an abundant number, since it is smaller than the sum of its proper divisors (99542420).

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

79821100 is a wasteful number, since it uses less digits than its factorization.

79821100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 79821100 is about 8934.2654986294. The cubic root of 79821100 is about 430.5655079828.

Adding to 79821100 its reverse (112897), we get a palindrome (79933997).

The spelling of 79821100 in words is "seventy-nine million, eight hundred twenty-one thousand, one hundred".