81881274 has 8 divisors (see below), whose sum is σ = 163762560. Its totient is φ = 27293756.

The previous prime is 81881273. The next prime is 81881287. The reversal of 81881274 is 47218818.

It is a happy number.

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

81881274 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (81881273) 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 3 ways as a sum of consecutive naturals, for example, 6823434 + ... + 6823445.

It is an arithmetic number, because the mean of its divisors is an integer number (20470320).

Almost surely, 2^81881274 is an apocalyptic number.

81881274 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81881274 is a wasteful number, since it uses less digits than its factorization.

81881274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13646884.

The product of its digits is 28672, while the sum is 39.

The square root of 81881274 is about 9048.8272168276. The cubic root of 81881274 is about 434.2383713211.

The spelling of 81881274 in words is "eighty-one million, eight hundred eighty-one thousand, two hundred seventy-four".