43215541 has 2 divisors, whose sum is σ = 43215542. Its totient is φ = 43215540.

The previous prime is 43215533. The next prime is 43215587. The reversal of 43215541 is 14551234.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26780625 + 16434916 = 5175^2 + 4054^2 .

It is a cyclic number.

It is not a de Polignac number, because 43215541 - 2³ = 43215533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43215521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21607770 + 21607771.

It is an arithmetic number, because the mean of its divisors is an integer number (21607771).

Almost surely, 2^43215541 is an apocalyptic number.

It is an amenable number.

43215541 is a deficient number, since it is larger than the sum of its proper divisors (1).

43215541 is an equidigital number, since it uses as much as digits as its factorization.

43215541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2400, while the sum is 25.

The square root of 43215541 is about 6573.8528276803. The cubic root of 43215541 is about 350.9241996148.

Adding to 43215541 its reverse (14551234), we get a palindrome (57766775).

The spelling of 43215541 in words is "forty-three million, two hundred fifteen thousand, five hundred forty-one".