123100031 has 4 divisors (see below), whose sum is σ = 129579000. Its totient is φ = 116621064.

The previous prime is 123099997. The next prime is 123100051. The reversal of 123100031 is 130001321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 123100031 - 2⁶ = 123099967 is a prime.

It is a super-2 number, since 2×123100031² = 30307235264401922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123099985 and 123100021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123100051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3239456 + ... + 3239493.

It is an arithmetic number, because the mean of its divisors is an integer number (32394750).

Almost surely, 2^123100031 is an apocalyptic number.

123100031 is a deficient number, since it is larger than the sum of its proper divisors (6478969).

123100031 is an equidigital number, since it uses as much as digits as its factorization.

123100031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6478968.

The product of its (nonzero) digits is 18, while the sum is 11.

The square root of 123100031 is about 11095.0453356442. The cubic root of 123100031 is about 497.4537633688.

Adding to 123100031 its reverse (130001321), we get a palindrome (253101352).

The spelling of 123100031 in words is "one hundred twenty-three million, one hundred thousand, thirty-one".