235981 has 4 divisors (see below), whose sum is σ = 236992. Its totient is φ = 234972.

The previous prime is 235979. The next prime is 235997. The reversal of 235981 is 189532.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 235981 - 2¹ = 235979 is a prime.

It is a super-2 number, since 2×235981² = 111374064722, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (235901) 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, 46 + ... + 688.

It is an arithmetic number, because the mean of its divisors is an integer number (59248).

2²³⁵⁹⁸¹ is an apocalyptic number.

It is an amenable number.

235981 is a deficient number, since it is larger than the sum of its proper divisors (1011).

235981 is an equidigital number, since it uses as much as digits as its factorization.

235981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010.

The product of its digits is 2160, while the sum is 28.

The square root of 235981 is about 485.7787562255. The cubic root of 235981 is about 61.7958076076.

The spelling of 235981 in words is "two hundred thirty-five thousand, nine hundred eighty-one".