78172384 has 72 divisors (see below), whose sum is σ = 166484808. Its totient is φ = 36115200.

The previous prime is 78172373. The next prime is 78172387. The reversal of 78172384 is 48327187.

It is a super-2 number, since 2×78172384² = 12221843240486912, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78172387) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 773934 + ... + 774034.

It is an arithmetic number, because the mean of its divisors is an integer number (2312289).

Almost surely, 2^78172384 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 78172384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83242404).

78172384 is an abundant number, since it is smaller than the sum of its proper divisors (88312424).

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

78172384 is a wasteful number, since it uses less digits than its factorization.

78172384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 189 counting only the distinct ones).

The product of its digits is 75264, while the sum is 40.

The square root of 78172384 is about 8841.5148023402. The cubic root of 78172384 is about 427.5803964022.

It can be divided in two parts, 7817 and 2384, that added together give a palindrome (10201).

The spelling of 78172384 in words is "seventy-eight million, one hundred seventy-two thousand, three hundred eighty-four".