78945181 has 4 divisors (see below), whose sum is σ = 90223072. Its totient is φ = 67667292.

The previous prime is 78945157. The next prime is 78945187. The reversal of 78945181 is 18154987.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18154987 = 43 ⋅422209.

It is not a de Polignac number, because 78945181 - 2⁵ = 78945149 is a prime.

It is a super-2 number, since 2×78945181² = 12464683206245522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78945187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5638935 + ... + 5638948.

It is an arithmetic number, because the mean of its divisors is an integer number (22555768).

Almost surely, 2^78945181 is an apocalyptic number.

It is an amenable number.

78945181 is a deficient number, since it is larger than the sum of its proper divisors (11277891).

78945181 is a wasteful number, since it uses less digits than its factorization.

78945181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11277890.

The product of its digits is 80640, while the sum is 43.

The square root of 78945181 is about 8885.1100724752. The cubic root of 78945181 is about 428.9847709686.

The spelling of 78945181 in words is "seventy-eight million, nine hundred forty-five thousand, one hundred eighty-one".