1388490509 has 6 divisors (see below), whose sum is σ = 1615182894. Its totient is φ = 1190134680.

The previous prime is 1388490503. The next prime is 1388490517. The reversal of 1388490509 is 9050948831.

It can be written as a sum of positive squares in only one way, i.e., 1107425284 + 281065225 = 33278^2 + 16765^2 .

It is not a de Polignac number, because 1388490509 - 2²⁴ = 1371713293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388490503) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14168222 + ... + 14168319.

It is an arithmetic number, because the mean of its divisors is an integer number (269197149).

Almost surely, 2^1388490509 is an apocalyptic number.

It is an amenable number.

1388490509 is a deficient number, since it is larger than the sum of its proper divisors (226692385).

1388490509 is an equidigital number, since it uses as much as digits as its factorization.

1388490509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28336555 (or 28336548 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 47.

The square root of 1388490509 is about 37262.4544145981. The cubic root of 1388490509 is about 1115.6148978196.

The spelling of 1388490509 in words is "one billion, three hundred eighty-eight million, four hundred ninety thousand, five hundred nine".