43391013121 has 2 divisors, whose sum is σ = 43391013122. Its totient is φ = 43391013120.

The previous prime is 43391013073. The next prime is 43391013191. The reversal of 43391013121 is 12131019334.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42617060721 + 773952400 = 206439^2 + 27820^2 .

It is a cyclic number.

It is not a de Polignac number, because 43391013121 - 2¹⁹ = 43390488833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 43391013121.

It is not a weakly prime, because it can be changed into another prime (43391013191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21695506560 + 21695506561.

It is an arithmetic number, because the mean of its divisors is an integer number (21695506561).

Almost surely, 2^43391013121 is an apocalyptic number.

It is an amenable number.

43391013121 is a deficient number, since it is larger than the sum of its proper divisors (1).

43391013121 is an equidigital number, since it uses as much as digits as its factorization.

43391013121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 28.

The spelling of 43391013121 in words is "forty-three billion, three hundred ninety-one million, thirteen thousand, one hundred twenty-one".