123686321 has 6 divisors (see below), whose sum is σ = 135952866. Its totient is φ = 112442000.

The previous prime is 123686279. The next prime is 123686347.

123686321 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 121000000 + 2686321 = 11000^2 + 1639^2 .

It is not a de Polignac number, because 123686321 - 2²² = 119492017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123686021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 510980 + ... + 511221.

It is an arithmetic number, because the mean of its divisors is an integer number (22658811).

Almost surely, 2^123686321 is an apocalyptic number.

123686321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

123686321 is a deficient number, since it is larger than the sum of its proper divisors (12266545).

123686321 is a wasteful number, since it uses less digits than its factorization.

123686321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1022223 (or 1022212 counting only the distinct ones).

The product of its digits is 10368, while the sum is 32.

The square root of 123686321 is about 11121.4352041452. The cubic root of 123686321 is about 498.2422559126.

The spelling of 123686321 in words is "one hundred twenty-three million, six hundred eighty-six thousand, three hundred twenty-one".