123856129 has 8 divisors (see below), whose sum is σ = 132261120. Its totient is φ = 115726800.

The previous prime is 123856123. The next prime is 123856141. The reversal of 123856129 is 921658321.

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

It is a cyclic number.

It is not a de Polignac number, because 123856129 - 2⁵ = 123856097 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123856123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67987 + ... + 69784.

It is an arithmetic number, because the mean of its divisors is an integer number (16532640).

Almost surely, 2^123856129 is an apocalyptic number.

It is an amenable number.

123856129 is a deficient number, since it is larger than the sum of its proper divisors (8404991).

123856129 is a wasteful number, since it uses less digits than its factorization.

123856129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137831.

The product of its digits is 25920, while the sum is 37.

The square root of 123856129 is about 11129.0668521669. The cubic root of 123856129 is about 498.4701626359.

The spelling of 123856129 in words is "one hundred twenty-three million, eight hundred fifty-six thousand, one hundred twenty-nine".