123121005 has 32 divisors (see below), whose sum is σ = 226879488. Its totient is φ = 55848000.

The previous prime is 123121003. The next prime is 123121013. The reversal of 123121005 is 500121321.

It is not a de Polignac number, because 123121005 - 2¹ = 123121003 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123121003) 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 31 ways as a sum of consecutive naturals, for example, 9280 + ... + 18230.

It is an arithmetic number, because the mean of its divisors is an integer number (7089984).

Almost surely, 2^123121005 is an apocalyptic number.

123121005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

123121005 is a deficient number, since it is larger than the sum of its proper divisors (103758483).

123121005 is a wasteful number, since it uses less digits than its factorization.

123121005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9097.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 123121005 is about 11095.9904920651. The cubic root of 123121005 is about 497.4820141137.

Adding to 123121005 its reverse (500121321), we get a palindrome (623242326).

The spelling of 123121005 in words is "one hundred twenty-three million, one hundred twenty-one thousand, five".