79891900 has 72 divisors (see below), whose sum is σ = 192487680. Its totient is φ = 28536000.

The previous prime is 79891879. The next prime is 79891901. The reversal of 79891900 is 919897.

It is a super-2 number, since 2×79891900² = 12765431371220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79891901) 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, 64285 + ... + 65515.

It is an arithmetic number, because the mean of its divisors is an integer number (2673440).

Almost surely, 2^79891900 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 79891900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96243840).

79891900 is an abundant number, since it is smaller than the sum of its proper divisors (112595780).

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

79891900 is a wasteful number, since it uses less digits than its factorization.

79891900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1315 (or 1308 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 79891900 is about 8938.2268935175. The cubic root of 79891900 is about 430.6927718661.

It can be divided in two parts, 7989 and 1900, that added together give a palindrome (9889).

The spelling of 79891900 in words is "seventy-nine million, eight hundred ninety-one thousand, nine hundred".