81813274 has 12 divisors (see below), whose sum is σ = 123395562. Its totient is φ = 40682520.

The previous prime is 81813241. The next prime is 81813283. The reversal of 81813274 is 47231818.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 79977249 + 1836025 = 8943^2 + 1355^2 .

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 146604 + ... + 147160.

Almost surely, 2^81813274 is an apocalyptic number.

81813274 is a deficient number, since it is larger than the sum of its proper divisors (41582288).

81813274 is an equidigital number, since it uses as much as digits as its factorization.

81813274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101 (or 830 counting only the distinct ones).

The product of its digits is 10752, while the sum is 34.

The square root of 81813274 is about 9045.0690434070. The cubic root of 81813274 is about 434.1181306129.

The spelling of 81813274 in words is "eighty-one million, eight hundred thirteen thousand, two hundred seventy-four".