43609961021 has 6 divisors (see below), whose sum is σ = 47934915966. Its totient is φ = 39645419000.

The previous prime is 43609960969. The next prime is 43609961023. The reversal of 43609961021 is 12016990634.

It can be written as a sum of positive squares in only one way, i.e., 36000888121 + 7609072900 = 189739^2 + 87230^2 .

It is a de Polignac number, because none of the positive numbers 2^k-43609961021 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 43609961021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43609961023) 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 5 ways as a sum of consecutive naturals, for example, 180206330 + ... + 180206571.

It is an arithmetic number, because the mean of its divisors is an integer number (7989152661).

Almost surely, 2^43609961021 is an apocalyptic number.

It is an amenable number.

43609961021 is a deficient number, since it is larger than the sum of its proper divisors (4324954945).

43609961021 is a wasteful number, since it uses less digits than its factorization.

43609961021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360412923 (or 360412912 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 41.

The spelling of 43609961021 in words is "forty-three billion, six hundred nine million, nine hundred sixty-one thousand, twenty-one".