1378609 has 4 divisors (see below), whose sum is σ = 1381104. Its totient is φ = 1376116.

The previous prime is 1378603. The next prime is 1378613. The reversal of 1378609 is 9068731.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9068731 = 7 ⋅1295533.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1378609 is a prime.

It is a Duffinian number.

1378609 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1378603) 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, 7 + ... + 1660.

It is an arithmetic number, because the mean of its divisors is an integer number (345276).

2^1378609 is an apocalyptic number.

It is an amenable number.

1378609 is a deficient number, since it is larger than the sum of its proper divisors (2495).

1378609 is an equidigital number, since it uses as much as digits as its factorization.

1378609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2494.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 1378609 is about 1174.1418142627. The cubic root of 1378609 is about 111.2962085533.

The spelling of 1378609 in words is "one million, three hundred seventy-eight thousand, six hundred nine".