78181872 has 40 divisors (see below), whose sum is σ = 204250320. Its totient is φ = 25766400.

The previous prime is 78181867. The next prime is 78181879. The reversal of 78181872 is 27818187.

It is a super-2 number, since 2×78181872² = 12224810218848768, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78181879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4879 + ... + 13422.

It is an arithmetic number, because the mean of its divisors is an integer number (5106258).

Almost surely, 2^78181872 is an apocalyptic number.

It is an amenable number.

78181872 is an abundant number, since it is smaller than the sum of its proper divisors (126068448).

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

78181872 is a wasteful number, since it uses less digits than its factorization.

78181872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18401 (or 18395 counting only the distinct ones).

The product of its digits is 50176, while the sum is 42.

The square root of 78181872 is about 8842.0513457003. The cubic root of 78181872 is about 427.5976945770.

The spelling of 78181872 in words is "seventy-eight million, one hundred eighty-one thousand, eight hundred seventy-two".