38928509 has 2 divisors, whose sum is σ = 38928510. Its totient is φ = 38928508.

The previous prime is 38928499. The next prime is 38928517. The reversal of 38928509 is 90582983.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37884025 + 1044484 = 6155^2 + 1022^2 .

It is a cyclic number.

It is not a de Polignac number, because 38928509 - 2⁴ = 38928493 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 38928509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38928569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19464254 + 19464255.

It is an arithmetic number, because the mean of its divisors is an integer number (19464255).

Almost surely, 2^38928509 is an apocalyptic number.

It is an amenable number.

38928509 is a deficient number, since it is larger than the sum of its proper divisors (1).

38928509 is an equidigital number, since it uses as much as digits as its factorization.

38928509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 38928509 is about 6239.2715119636. The cubic root of 38928509 is about 338.9138029440.

The spelling of 38928509 in words is "thirty-eight million, nine hundred twenty-eight thousand, five hundred nine".