123881 has 4 divisors (see below), whose sum is σ = 125652. Its totient is φ = 122112.

The previous prime is 123863. The next prime is 123887. The reversal of 123881 is 188321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 188321 = 7 ⋅26903.

It can be written as a sum of positive squares in 2 ways, for example, as 99856 + 24025 = 316^2 + 155^2 .

It is a cyclic number.

It is not a de Polignac number, because 123881 - 2⁶ = 123817 is a prime.

It is a super-2 number, since 2×123881² = 30693004322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123887) 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, 776 + ... + 921.

It is an arithmetic number, because the mean of its divisors is an integer number (31413).

2¹²³⁸⁸¹ is an apocalyptic number.

It is an amenable number.

123881 is a deficient number, since it is larger than the sum of its proper divisors (1771).

123881 is an equidigital number, since it uses as much as digits as its factorization.

123881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1770.

The product of its digits is 384, while the sum is 23.

The square root of 123881 is about 351.9673280292. The cubic root of 123881 is about 49.8503525597.

Adding to 123881 its sum of digits (23), we get a square (123904 = 352²).

The spelling of 123881 in words is "one hundred twenty-three thousand, eight hundred eighty-one".