79747578 has 80 divisors (see below), whose sum is σ = 197588160. Its totient is φ = 23912064.

The previous prime is 79747571. The next prime is 79747589. The reversal of 79747578 is 87574797.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (79747571) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 62713 + ... + 63971.

It is an arithmetic number, because the mean of its divisors is an integer number (2469852).

Almost surely, 2^79747578 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 79747578, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98794080).

79747578 is an abundant number, since it is smaller than the sum of its proper divisors (117840582).

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

79747578 is a wasteful number, since it uses less digits than its factorization.

79747578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1313 (or 1304 counting only the distinct ones).

The product of its digits is 3457440, while the sum is 54.

The square root of 79747578 is about 8930.1499427501. The cubic root of 79747578 is about 430.4332715961.

The spelling of 79747578 in words is "seventy-nine million, seven hundred forty-seven thousand, five hundred seventy-eight".