43634521 has 4 divisors (see below), whose sum is σ = 49868032. Its totient is φ = 37401012.

The previous prime is 43634491. The next prime is 43634527. The reversal of 43634521 is 12543634.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12543634 = 2 ⋅6271817.

It is a cyclic number.

It is not a de Polignac number, because 43634521 - 2⁵ = 43634489 is a prime.

It is an alternating number because its digits alternate between even and odd.

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 43634521.

It is not an unprimeable number, because it can be changed into a prime (43634527) 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, 3116745 + ... + 3116758.

It is an arithmetic number, because the mean of its divisors is an integer number (12467008).

Almost surely, 2^43634521 is an apocalyptic number.

It is an amenable number.

43634521 is a deficient number, since it is larger than the sum of its proper divisors (6233511).

43634521 is an equidigital number, since it uses as much as digits as its factorization.

43634521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6233510.

The product of its digits is 8640, while the sum is 28.

The square root of 43634521 is about 6605.6431178198. The cubic root of 43634521 is about 352.0546386645.

The spelling of 43634521 in words is "forty-three million, six hundred thirty-four thousand, five hundred twenty-one".