81389286 has 40 divisors (see below), whose sum is σ = 198955944. Its totient is φ = 24662880.

The previous prime is 81389281. The next prime is 81389333. The reversal of 81389286 is 68298318.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81389281) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 21055 + ... + 24618.

Almost surely, 2^81389286 is an apocalyptic number.

81389286 is an abundant number, since it is smaller than the sum of its proper divisors (117566658).

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

81389286 is a wasteful number, since it uses less digits than its factorization.

81389286 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45698 (or 45689 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 81389286 is about 9021.6010774141. The cubic root of 81389286 is about 433.3669087725.

It can be divided in two parts, 8138 and 9286, that added together give a square (17424 = 132²).

The spelling of 81389286 in words is "eighty-one million, three hundred eighty-nine thousand, two hundred eighty-six".