123898 has 4 divisors (see below), whose sum is σ = 185850. Its totient is φ = 61948.

The previous prime is 123887. The next prime is 123911. The reversal of 123898 is 898321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 898321 = 149 ⋅6029.

It can be written as a sum of positive squares in only one way, i.e., 100489 + 23409 = 317^2 + 153^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30973 + ... + 30976.

2¹²³⁸⁹⁸ is an apocalyptic number.

123898 is a deficient number, since it is larger than the sum of its proper divisors (61952).

123898 is an equidigital number, since it uses as much as digits as its factorization.

123898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61951.

The product of its digits is 3456, while the sum is 31.

The square root of 123898 is about 351.9914771695. The cubic root of 123898 is about 49.8526327513.

The spelling of 123898 in words is "one hundred twenty-three thousand, eight hundred ninety-eight".