123240105 has 24 divisors (see below), whose sum is σ = 217650888. Its totient is φ = 64486656.

The previous prime is 123240083. The next prime is 123240109. The reversal of 123240105 is 501042321.

It can be written as a sum of positive squares in 4 ways, for example, as 60466176 + 62773929 = 7776^2 + 7923^2 .

It is not a de Polignac number, because 123240105 - 2¹¹ = 123238057 is a prime.

It is a super-2 number, since 2×123240105² = 30376246960822050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (123240109) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23452 + ... + 28221.

It is an arithmetic number, because the mean of its divisors is an integer number (9068787).

Almost surely, 2^123240105 is an apocalyptic number.

123240105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

123240105 is a deficient number, since it is larger than the sum of its proper divisors (94410783).

123240105 is a wasteful number, since it uses less digits than its factorization.

123240105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51737 (or 51734 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 123240105 is about 11101.3559982553. The cubic root of 123240105 is about 497.6423740055.

Adding to 123240105 its reverse (501042321), we get a palindrome (624282426).

The spelling of 123240105 in words is "one hundred twenty-three million, two hundred forty thousand, one hundred five".