78818181 has 8 divisors (see below), whose sum is σ = 113174880. Its totient is φ = 48503472.

The previous prime is 78818149. The next prime is 78818191. The reversal of 78818181 is 18181887.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78818181 - 2⁵ = 78818149 is a prime.

It is a super-2 number, since 2×78818181² = 12424611312297522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78818101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1010451 + ... + 1010528.

It is an arithmetic number, because the mean of its divisors is an integer number (14146860).

Almost surely, 2^78818181 is an apocalyptic number.

It is an amenable number.

78818181 is a deficient number, since it is larger than the sum of its proper divisors (34356699).

78818181 is a wasteful number, since it uses less digits than its factorization.

78818181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2020995.

The product of its digits is 28672, while the sum is 42.

The square root of 78818181 is about 8877.9604076612. The cubic root of 78818181 is about 428.7546099627.

It can be divided in two parts, 7 and 8818181, that added together give a palindrome (8818188).

The spelling of 78818181 in words is "seventy-eight million, eight hundred eighteen thousand, one hundred eighty-one".