1380642649 has 9 divisors (see below), whose sum is σ = 1402570173. Its totient is φ = 1359054432.

The previous prime is 1380642647. The next prime is 1380642661. The reversal of 1380642649 is 9462460831.

It is a happy number.

The square root of 1380642649 is 37157.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 215649225 + 1164993424 = 14685^2 + 34132^2 .

It is not a de Polignac number, because 1380642649 - 2¹ = 1380642647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1380642647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2712207 + ... + 2712715.

Almost surely, 2^1380642649 is an apocalyptic number.

1380642649 is the 37157-th square number.

1380642649 is the 18579-th centered octagonal number.

It is an amenable number.

1380642649 is a deficient number, since it is larger than the sum of its proper divisors (21927524).

1380642649 is an frugal number, since it uses more digits than its factorization.

1380642649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1164 (or 582 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 43.

The cubic root of 1380642649 is about 1113.5090770312.

The spelling of 1380642649 in words is "one billion, three hundred eighty million, six hundred forty-two thousand, six hundred forty-nine".