78387912 has 56 divisors (see below), whose sum is σ = 220381590. Its totient is φ = 26127360.

The previous prime is 78387889. The next prime is 78387913. The reversal of 78387912 is 21978387.

It can be written as a sum of positive squares in only one way, i.e., 75585636 + 2802276 = 8694^2 + 1674^2 .

It is a super-2 number, since 2×78387912² = 12289329495439488, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78387913) 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 13 ways as a sum of consecutive naturals, for example, 889 + ... + 12552.

Almost surely, 2^78387912 is an apocalyptic number.

78387912 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78387912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110190795).

78387912 is an abundant number, since it is smaller than the sum of its proper divisors (141993678).

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

78387912 is a wasteful number, since it uses less digits than its factorization.

78387912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13465 (or 13446 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 78387912 is about 8853.6948219373. The cubic root of 78387912 is about 427.9729944821.

The spelling of 78387912 in words is "seventy-eight million, three hundred eighty-seven thousand, nine hundred twelve".