1387782728 has 16 divisors (see below), whose sum is σ = 2602577580. Its totient is φ = 693762048.

The previous prime is 1387782727. The next prime is 1387782749. The reversal of 1387782728 is 8272877831.

It can be written as a sum of positive squares in 2 ways, for example, as 1382203684 + 5579044 = 37178^2 + 2362^2 .

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1387782728.

It is not an unprimeable number, because it can be changed into a prime (1387782727) 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, 41576 + ... + 67112.

Almost surely, 2^1387782728 is an apocalyptic number.

It is an amenable number.

1387782728 is a deficient number, since it is larger than the sum of its proper divisors (1214794852).

1387782728 is a wasteful number, since it uses less digits than its factorization.

1387782728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32336 (or 32332 counting only the distinct ones).

The product of its digits is 2107392, while the sum is 53.

The square root of 1387782728 is about 37252.9559632521. The cubic root of 1387782728 is about 1115.4253045818.

The spelling of 1387782728 in words is "one billion, three hundred eighty-seven million, seven hundred eighty-two thousand, seven hundred twenty-eight".