1378645 has 4 divisors (see below), whose sum is σ = 1654380. Its totient is φ = 1102912.

The previous prime is 1378639. The next prime is 1378669. The reversal of 1378645 is 5468731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5468731 = 1759 ⋅3109.

It can be written as a sum of positive squares in 2 ways, for example, as 935089 + 443556 = 967^2 + 666^2 .

It is a cyclic number.

It is not a de Polignac number, because 1378645 - 2⁵ = 1378613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1378645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137860 + ... + 137869.

It is an arithmetic number, because the mean of its divisors is an integer number (413595).

2^1378645 is an apocalyptic number.

It is an amenable number.

1378645 is a deficient number, since it is larger than the sum of its proper divisors (275735).

1378645 is an equidigital number, since it uses as much as digits as its factorization.

1378645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275734.

The product of its digits is 20160, while the sum is 34.

The square root of 1378645 is about 1174.1571445083. The cubic root of 1378645 is about 111.2971773145.

It can be divided in two parts, 13786 and 45, that added together give a palindrome (13831).

The spelling of 1378645 in words is "one million, three hundred seventy-eight thousand, six hundred forty-five".