43123121 has 4 divisors (see below), whose sum is σ = 43283700. Its totient is φ = 42962544.

The previous prime is 43123099. The next prime is 43123127. The reversal of 43123121 is 12132134.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10758400 + 32364721 = 3280^2 + 5689^2 .

It is a cyclic number.

It is not a de Polignac number, because 43123121 - 2¹⁸ = 42860977 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 43123121.

It is not an unprimeable number, because it can be changed into a prime (43123127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79886 + ... + 80423.

It is an arithmetic number, because the mean of its divisors is an integer number (10820925).

Almost surely, 2^43123121 is an apocalyptic number.

It is an amenable number.

43123121 is a deficient number, since it is larger than the sum of its proper divisors (160579).

43123121 is a wasteful number, since it uses less digits than its factorization.

43123121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160578.

The product of its digits is 144, while the sum is 17.

The square root of 43123121 is about 6566.8197021085. The cubic root of 43123121 is about 350.6738609551.

Adding to 43123121 its reverse (12132134), we get a palindrome (55255255).

The spelling of 43123121 in words is "forty-three million, one hundred twenty-three thousand, one hundred twenty-one".