43557212161 has 4 divisors (see below), whose sum is σ = 43797859924. Its totient is φ = 43316564400.

The previous prime is 43557212089. The next prime is 43557212173. The reversal of 43557212161 is 16121275534.

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 2730585025 + 40826627136 = 52255^2 + 202056^2 .

It is a cyclic number.

It is not a de Polignac number, because 43557212161 - 2¹³ = 43557203969 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 43557212161.

It is not an unprimeable number, because it can be changed into a prime (43557212861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120323610 + ... + 120323971.

It is an arithmetic number, because the mean of its divisors is an integer number (10949464981).

Almost surely, 2^43557212161 is an apocalyptic number.

It is an amenable number.

43557212161 is a deficient number, since it is larger than the sum of its proper divisors (240647763).

43557212161 is a wasteful number, since it uses less digits than its factorization.

43557212161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240647762.

The product of its digits is 50400, while the sum is 37.

Adding to 43557212161 its reverse (16121275534), we get a palindrome (59678487695).

The spelling of 43557212161 in words is "forty-three billion, five hundred fifty-seven million, two hundred twelve thousand, one hundred sixty-one".