239981 has 4 divisors (see below), whose sum is σ = 274272. Its totient is φ = 205692.

The previous prime is 239977. The next prime is 239999. The reversal of 239981 is 189932.

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.

It is a cyclic number.

It is not a de Polignac number, because 239981 - 2² = 239977 is a prime.

It is a super-2 number, since 2×239981² = 115181760722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (239081) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 17135 + ... + 17148.

It is an arithmetic number, because the mean of its divisors is an integer number (68568).

2²³⁹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

239981 is a deficient number, since it is larger than the sum of its proper divisors (34291).

239981 is an equidigital number, since it uses as much as digits as its factorization.

239981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34290.

The product of its digits is 3888, while the sum is 32.

The square root of 239981 is about 489.8785563790. The cubic root of 239981 is about 62.1430101475.

The spelling of 239981 in words is "two hundred thirty-nine thousand, nine hundred eighty-one".