43540221 has 16 divisors (see below), whose sum is σ = 58882880. Its totient is φ = 28615680.

The previous prime is 43540187. The next prime is 43540243. The reversal of 43540221 is 12204534.

It is a de Polignac number, because none of the positive numbers 2^k-43540221 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 (43540261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80211 + ... + 80751.

It is an arithmetic number, because the mean of its divisors is an integer number (3680180).

Almost surely, 2^43540221 is an apocalyptic number.

It is an amenable number.

43540221 is a deficient number, since it is larger than the sum of its proper divisors (15342659).

43540221 is a wasteful number, since it uses less digits than its factorization.

43540221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 43540221 is about 6598.5014207773. The cubic root of 43540221 is about 351.8008434579.

Adding to 43540221 its reverse (12204534), we get a palindrome (55744755).

The spelling of 43540221 in words is "forty-three million, five hundred forty thousand, two hundred twenty-one".