81814178 has 12 divisors (see below), whose sum is σ = 126131922. Its totient is φ = 39800160.

The previous prime is 81814163. The next prime is 81814199. The reversal of 81814178 is 87141818.

It can be written as a sum of positive squares in 3 ways, for example, as 79691329 + 2122849 = 8927^2 + 1457^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12203 + ... + 17678.

Almost surely, 2^81814178 is an apocalyptic number.

81814178 is a deficient number, since it is larger than the sum of its proper divisors (44317744).

81814178 is a wasteful number, since it uses less digits than its factorization.

81814178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29957 (or 29920 counting only the distinct ones).

The product of its digits is 14336, while the sum is 38.

The square root of 81814178 is about 9045.1190152479. The cubic root of 81814178 is about 434.1197295439.

The spelling of 81814178 in words is "eighty-one million, eight hundred fourteen thousand, one hundred seventy-eight".