43445021 has 4 divisors (see below), whose sum is σ = 43522752. Its totient is φ = 43367292.

The previous prime is 43445009. The next prime is 43445027. The reversal of 43445021 is 12054434.

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 43445021 - 2¹⁰ = 43443997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43445027) 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, 38021 + ... + 39146.

It is an arithmetic number, because the mean of its divisors is an integer number (10880688).

Almost surely, 2^43445021 is an apocalyptic number.

It is an amenable number.

43445021 is a deficient number, since it is larger than the sum of its proper divisors (77731).

43445021 is an equidigital number, since it uses as much as digits as its factorization.

43445021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77730.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 43445021 is about 6591.2837141182. The cubic root of 43445021 is about 351.5442540430.

Adding to 43445021 its reverse (12054434), we get a palindrome (55499455).

The spelling of 43445021 in words is "forty-three million, four hundred forty-five thousand, twenty-one".