123890 has 16 divisors (see below), whose sum is σ = 240408. Its totient is φ = 45696.

The previous prime is 123887. The next prime is 123911. The reversal of 123890 is 98321.

It can be written as a sum of positive squares in 4 ways, for example, as 72361 + 51529 = 269^2 + 227^2 .

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is an unprimeable 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 in 7 ways as a sum of consecutive naturals, for example, 347 + ... + 606.

2¹²³⁸⁹⁰ is an apocalyptic number.

123890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

123890 is a deficient number, since it is larger than the sum of its proper divisors (116518).

123890 is a wasteful number, since it uses less digits than its factorization.

123890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 973.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 123890 is about 351.9801130746. The cubic root of 123890 is about 49.8515597459.

The spelling of 123890 in words is "one hundred twenty-three thousand, eight hundred ninety".