43220561 has 4 divisors (see below), whose sum is σ = 43865712. Its totient is φ = 42575412.

The previous prime is 43220557. The next prime is 43220563. The reversal of 43220561 is 16502234.

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 43220561 - 2² = 43220557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (43220563) 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, 322475 + ... + 322608.

It is an arithmetic number, because the mean of its divisors is an integer number (10966428).

Almost surely, 2^43220561 is an apocalyptic number.

It is an amenable number.

43220561 is a deficient number, since it is larger than the sum of its proper divisors (645151).

43220561 is an equidigital number, since it uses as much as digits as its factorization.

43220561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645150.

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

The square root of 43220561 is about 6574.2346322595. The cubic root of 43220561 is about 350.9377870977.

Adding to 43220561 its reverse (16502234), we get a palindrome (59722795).

The spelling of 43220561 in words is "forty-three million, two hundred twenty thousand, five hundred sixty-one".