43521431 has 4 divisors (see below), whose sum is σ = 45022200. Its totient is φ = 42020664.

The previous prime is 43521421. The next prime is 43521433. The reversal of 43521431 is 13412534.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13412534 = 2 ⋅6706267.

It is a cyclic number.

It is not a de Polignac number, because 43521431 - 2¹⁴ = 43505047 is a prime.

It is a super-2 number, since 2×43521431² = 3788229912575522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 43521397 and 43521406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43521433) 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, 750341 + ... + 750398.

It is an arithmetic number, because the mean of its divisors is an integer number (11255550).

Almost surely, 2^43521431 is an apocalyptic number.

43521431 is a deficient number, since it is larger than the sum of its proper divisors (1500769).

43521431 is a wasteful number, since it uses less digits than its factorization.

43521431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1500768.

The product of its digits is 1440, while the sum is 23.

The square root of 43521431 is about 6597.0774589965. The cubic root of 43521431 is about 351.7502290388.

Adding to 43521431 its reverse (13412534), we get a palindrome (56933965).

The spelling of 43521431 in words is "forty-three million, five hundred twenty-one thousand, four hundred thirty-one".