123981 has 24 divisors (see below), whose sum is σ = 206304. Its totient is φ = 65280.

The previous prime is 123979. The next prime is 123983. The reversal of 123981 is 189321.

It is an interprime number because it is at equal distance from previous prime (123979) and next prime (123983).

It is not a de Polignac number, because 123981 - 2¹ = 123979 is a prime.

It is a super-2 number, since 2×123981² = 30742576722, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 123981.

It is not an unprimeable number, because it can be changed into a prime (123983) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7285 + ... + 7301.

It is an arithmetic number, because the mean of its divisors is an integer number (8596).

2¹²³⁹⁸¹ is an apocalyptic number.

123981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

123981 is a deficient number, since it is larger than the sum of its proper divisors (82323).

123981 is a wasteful number, since it uses less digits than its factorization.

123981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61 (or 44 counting only the distinct ones).

The product of its digits is 432, while the sum is 24.

The square root of 123981 is about 352.1093580125. The cubic root of 123981 is about 49.8637624571.

It can be divided in two parts, 12 and 3981, that added together give a palindrome (3993).

The spelling of 123981 in words is "one hundred twenty-three thousand, nine hundred eighty-one".