39881 has 4 divisors (see below), whose sum is σ = 42000. Its totient is φ = 37764.

The previous prime is 39877. The next prime is 39883. The reversal of 39881 is 18893.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18893 = 7 ⋅2699.

It is a cyclic number.

It is not a de Polignac number, because 39881 - 2² = 39877 is a prime.

It is a super-2 number, since 2×39881² = 3180988322, which contains 22 as substring.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 39881.

It is not an unprimeable number, because it can be changed into a prime (39883) 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, 1031 + ... + 1068.

It is an arithmetic number, because the mean of its divisors is an integer number (10500).

2³⁹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

39881 is a deficient number, since it is larger than the sum of its proper divisors (2119).

39881 is a wasteful number, since it uses less digits than its factorization.

39881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2118.

The product of its digits is 1728, while the sum is 29.

The square root of 39881 is about 199.7022784046. The cubic root of 39881 is about 34.1655707230.

The spelling of 39881 in words is "thirty-nine thousand, eight hundred eighty-one".