39923509 has 2 divisors, whose sum is σ = 39923510. Its totient is φ = 39923508.

The previous prime is 39923501. The next prime is 39923563. The reversal of 39923509 is 90532993.

39923509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31640625 + 8282884 = 5625^2 + 2878^2 .

It is an emirp because it is prime and its reverse (90532993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39923509 - 2³ = 39923501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39923501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19961754 + 19961755.

It is an arithmetic number, because the mean of its divisors is an integer number (19961755).

Almost surely, 2^39923509 is an apocalyptic number.

It is an amenable number.

39923509 is a deficient number, since it is larger than the sum of its proper divisors (1).

39923509 is an equidigital number, since it uses as much as digits as its factorization.

39923509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 65610, while the sum is 40.

The square root of 39923509 is about 6318.5052821059. The cubic root of 39923509 is about 341.7770539477. Note that the first 3 decimals are identical.

The spelling of 39923509 in words is "thirty-nine million, nine hundred twenty-three thousand, five hundred nine".