1378729 has 4 divisors (see below), whose sum is σ = 1504080. Its totient is φ = 1253380.

The previous prime is 1378721. The next prime is 1378733. The reversal of 1378729 is 9278731.

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.

It is a cyclic number.

It is not a de Polignac number, because 1378729 - 2³ = 1378721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1378721) 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, 62659 + ... + 62680.

It is an arithmetic number, because the mean of its divisors is an integer number (376020).

2^1378729 is an apocalyptic number.

It is an amenable number.

1378729 is a deficient number, since it is larger than the sum of its proper divisors (125351).

1378729 is a wasteful number, since it uses less digits than its factorization.

1378729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125350.

The product of its digits is 21168, while the sum is 37.

The square root of 1378729 is about 1174.1929143033. The cubic root of 1378729 is about 111.2994376916.

The spelling of 1378729 in words is "one million, three hundred seventy-eight thousand, seven hundred twenty-nine".