81988 has 12 divisors (see below), whose sum is σ = 145600. Its totient is φ = 40392.

The previous prime is 81973. The next prime is 82003. The reversal of 81988 is 88918.

81988 is nontrivially palindromic in base 11.

It is an interprime number because it is at equal distance from previous prime (81973) and next prime (82003).

It is an unprimeable number.

81988 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313 + ... + 511.

2⁸¹⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

81988 is a deficient number, since it is larger than the sum of its proper divisors (63612).

81988 is a wasteful number, since it uses less digits than its factorization.

81988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306 (or 304 counting only the distinct ones).

The product of its digits is 4608, while the sum is 34.

The square root of 81988 is about 286.3354675900. The cubic root of 81988 is about 43.4426954950.

The spelling of 81988 in words is "eighty-one thousand, nine hundred eighty-eight".