79121664 has 72 divisors (see below), whose sum is σ = 233997120. Its totient is φ = 26371584.

The previous prime is 79121663. The next prime is 79121737. The reversal of 79121664 is 46612197.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79121663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1189 + ... + 12635.

It is an arithmetic number, because the mean of its divisors is an integer number (3249960).

Almost surely, 2^79121664 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 79121664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116998560).

79121664 is an abundant number, since it is smaller than the sum of its proper divisors (154875456).

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

79121664 is a wasteful number, since it uses less digits than its factorization.

79121664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11472 (or 11452 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 79121664 is about 8895.0359189831. The cubic root of 79121664 is about 429.3042001073.

The spelling of 79121664 in words is "seventy-nine million, one hundred twenty-one thousand, six hundred sixty-four".