123819 has 8 divisors (see below), whose sum is σ = 166800. Its totient is φ = 81696.

The previous prime is 123817. The next prime is 123821. The reversal of 123819 is 918321.

It is an interprime number because it is at equal distance from previous prime (123817) and next prime (123821).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 123819 - 2¹ = 123817 is a prime.

It is a super-2 number, since 2×123819² = 30662289522, which contains 22 as substring.

123819 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (123817) 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 7 ways as a sum of consecutive naturals, for example, 309 + ... + 585.

It is an arithmetic number, because the mean of its divisors is an integer number (20850).

2¹²³⁸¹⁹ is an apocalyptic number.

123819 is a deficient number, since it is larger than the sum of its proper divisors (42981).

123819 is a wasteful number, since it uses less digits than its factorization.

123819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429.

The product of its digits is 432, while the sum is 24.

The square root of 123819 is about 351.8792406494. The cubic root of 123819 is about 49.8420347988.

Adding to 123819 its product of digits (432), we get a triangular number (124251 = T₄₉₈).

The spelling of 123819 in words is "one hundred twenty-three thousand, eight hundred nineteen".