39972509 has 2 divisors, whose sum is σ = 39972510. Its totient is φ = 39972508.

The previous prime is 39972497. The next prime is 39972521. The reversal of 39972509 is 90527993.

It is a balanced prime because it is at equal distance from previous prime (39972497) and next prime (39972521).

It can be written as a sum of positive squares in only one way, i.e., 36060025 + 3912484 = 6005^2 + 1978^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39972509 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39972509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39972529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19986254 + 19986255.

It is an arithmetic number, because the mean of its divisors is an integer number (19986255).

Almost surely, 2^39972509 is an apocalyptic number.

It is an amenable number.

39972509 is a deficient number, since it is larger than the sum of its proper divisors (1).

39972509 is an equidigital number, since it uses as much as digits as its factorization.

39972509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 153090, while the sum is 44.

The square root of 39972509 is about 6322.3815924065. The cubic root of 39972509 is about 341.9168231316.

The spelling of 39972509 in words is "thirty-nine million, nine hundred seventy-two thousand, five hundred nine".