123690 has 64 divisors (see below), whose sum is σ = 368640. Its totient is φ = 25920.

The previous prime is 123677. The next prime is 123701. The reversal of 123690 is 96321.

It is a super-2 number, since 2×123690² = 30598432200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

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

It is a Curzon number.

It is a nialpdrome in base 14.

It is an unprimeable number.

123690 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3975 + ... + 4005.

It is an arithmetic number, because the mean of its divisors is an integer number (5760).

2¹²³⁶⁹⁰ is an apocalyptic number.

123690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 123690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184320).

123690 is an abundant number, since it is smaller than the sum of its proper divisors (244950).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123690 is a wasteful number, since it uses less digits than its factorization.

123690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 123690 is about 351.6958913607. The cubic root of 123690 is about 49.8247195869.

It can be divided in two parts, 1236 and 90, that added together give a triangular number (1326 = T₅₁).

The spelling of 123690 in words is "one hundred twenty-three thousand, six hundred ninety".