43209137 has 2 divisors, whose sum is σ = 43209138. Its totient is φ = 43209136.

The previous prime is 43209091. The next prime is 43209139. The reversal of 43209137 is 73190234.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31091776 + 12117361 = 5576^2 + 3481^2 .

It is a cyclic number.

It is not a de Polignac number, because 43209137 - 2⁶ = 43209073 is a prime.

Together with 43209139, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (43209139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21604568 + 21604569.

It is an arithmetic number, because the mean of its divisors is an integer number (21604569).

Almost surely, 2^43209137 is an apocalyptic number.

It is an amenable number.

43209137 is a deficient number, since it is larger than the sum of its proper divisors (1).

43209137 is an equidigital number, since it uses as much as digits as its factorization.

43209137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 43209137 is about 6573.3657284530. The cubic root of 43209137 is about 350.9068645733.

The spelling of 43209137 in words is "forty-three million, two hundred nine thousand, one hundred thirty-seven".