1378649225 has 18 divisors (see below), whose sum is σ = 1719490206. Its totient is φ = 1096513600.

The previous prime is 1378649201. The next prime is 1378649257. The reversal of 1378649225 is 5229468731.

It can be written as a sum of positive squares in 3 ways, for example, as 153859216 + 1224790009 = 12404^2 + 34997^2 .

It is not a de Polignac number, because 1378649225 - 2⁶ = 1378649161 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 1378649225.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3111854 + ... + 3112296.

Almost surely, 2^1378649225 is an apocalyptic number.

It is an amenable number.

1378649225 is a deficient number, since it is larger than the sum of its proper divisors (340840981).

1378649225 is an frugal number, since it uses more digits than its factorization.

1378649225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1177 (or 729 counting only the distinct ones).

The product of its digits is 725760, while the sum is 47.

The square root of 1378649225 is about 37130.1659705421. The cubic root of 1378649225 is about 1112.9729100824.

The spelling of 1378649225 in words is "one billion, three hundred seventy-eight million, six hundred forty-nine thousand, two hundred twenty-five".