43378561 has 4 divisors (see below), whose sum is σ = 43438000. Its totient is φ = 43319124.

The previous prime is 43378537. The next prime is 43378567. The reversal of 43378561 is 16587334.

43378561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 43378561 - 2¹¹ = 43376513 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 43378561.

It is not an unprimeable number, because it can be changed into a prime (43378567) 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 in 3 ways as a sum of consecutive naturals, for example, 28611 + ... + 30088.

It is an arithmetic number, because the mean of its divisors is an integer number (10859500).

Almost surely, 2^43378561 is an apocalyptic number.

It is an amenable number.

43378561 is a deficient number, since it is larger than the sum of its proper divisors (59439).

43378561 is an equidigital number, since it uses as much as digits as its factorization.

43378561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59438.

The product of its digits is 60480, while the sum is 37.

The square root of 43378561 is about 6586.2402780342. The cubic root of 43378561 is about 351.3649043406.

It can be divided in two parts, 433785 and 61, that added together give a triangular number (433846 = T₉₃₁).

The spelling of 43378561 in words is "forty-three million, three hundred seventy-eight thousand, five hundred sixty-one".