81289266 has 8 divisors (see below), whose sum is σ = 162578544. Its totient is φ = 27096420.

The previous prime is 81289231. The next prime is 81289267. The reversal of 81289266 is 66298218.

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

81289266 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (81289267) 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, 6774100 + ... + 6774111.

It is an arithmetic number, because the mean of its divisors is an integer number (20322318).

Almost surely, 2^81289266 is an apocalyptic number.

81289266 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.

81289266 is a wasteful number, since it uses less digits than its factorization.

81289266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13548216.

The product of its digits is 82944, while the sum is 42.

The square root of 81289266 is about 9016.0560113611. The cubic root of 81289266 is about 433.1893132179.

The spelling of 81289266 in words is "eighty-one million, two hundred eighty-nine thousand, two hundred sixty-six".