123742 has 4 divisors (see below), whose sum is σ = 185616. Its totient is φ = 61870.

The previous prime is 123737. The next prime is 123757. The reversal of 123742 is 247321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 247321 = 109 ⋅2269.

It is a congruent number.

It is an unprimeable number.

123742 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 30934 + ... + 30937.

It is an arithmetic number, because the mean of its divisors is an integer number (46404).

2¹²³⁷⁴² is an apocalyptic number.

123742 is a deficient number, since it is larger than the sum of its proper divisors (61874).

123742 is an equidigital number, since it uses as much as digits as its factorization.

123742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61873.

The product of its digits is 336, while the sum is 19.

The square root of 123742 is about 351.7698110981. The cubic root of 123742 is about 49.8317008099.

The spelling of 123742 in words is "one hundred twenty-three thousand, seven hundred forty-two", and thus it is an iban number.