81388 has 6 divisors (see below), whose sum is σ = 142436. Its totient is φ = 40692.

The previous prime is 81373. The next prime is 81401. The reversal of 81388 is 88318.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10170 + ... + 10177.

2⁸¹³⁸⁸ is an apocalyptic number.

It is an amenable number.

81388 is a deficient number, since it is larger than the sum of its proper divisors (61048).

81388 is a wasteful number, since it uses less digits than its factorization.

81388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20351 (or 20349 counting only the distinct ones).

The product of its digits is 1536, while the sum is 28.

The square root of 81388 is about 285.2858215895. The cubic root of 81388 is about 43.3364626274.

The spelling of 81388 in words is "eighty-one thousand, three hundred eighty-eight".