1388765249 has 4 divisors (see below), whose sum is σ = 1433564160. Its totient is φ = 1343966340.

The previous prime is 1388765239. The next prime is 1388765267. The reversal of 1388765249 is 9425678831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1388765249 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1388765249.

It is not an unprimeable number, because it can be changed into a prime (1388765219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22399409 + ... + 22399470.

It is an arithmetic number, because the mean of its divisors is an integer number (358391040).

Almost surely, 2^1388765249 is an apocalyptic number.

It is an amenable number.

1388765249 is a deficient number, since it is larger than the sum of its proper divisors (44798911).

1388765249 is an equidigital number, since it uses as much as digits as its factorization.

1388765249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44798910.

The product of its digits is 2903040, while the sum is 53.

The square root of 1388765249 is about 37266.1407849002. The cubic root of 1388765249 is about 1115.6884750416.

The spelling of 1388765249 in words is "one billion, three hundred eighty-eight million, seven hundred sixty-five thousand, two hundred forty-nine".