123731 has 2 divisors, whose sum is σ = 123732. Its totient is φ = 123730.

The previous prime is 123727. The next prime is 123733. The reversal of 123731 is 137321.

It is a strong prime.

It is an emirp because it is prime and its reverse (137321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123731 - 2² = 123727 is a prime.

It is a super-2 number, since 2×123731² = 30618720722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 123733, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (123733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61865 + 61866.

It is an arithmetic number, because the mean of its divisors is an integer number (61866).

2¹²³⁷³¹ is an apocalyptic number.

123731 is a deficient number, since it is larger than the sum of its proper divisors (1).

123731 is an equidigital number, since it uses as much as digits as its factorization.

123731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 126, while the sum is 17.

The square root of 123731 is about 351.7541755260. The cubic root of 123731 is about 49.8302241759.

It can be divided in two parts, 1 and 23731, that added together give a palindrome (23732).

The spelling of 123731 in words is "one hundred twenty-three thousand, seven hundred thirty-one".