1389778 has 8 divisors (see below), whose sum is σ = 2245068. Its totient is φ = 641424.

The previous prime is 1389769. The next prime is 1389797. The reversal of 1389778 is 8779831.

It can be written as a sum of positive squares in 2 ways, for example, as 1361889 + 27889 = 1167^2 + 167^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 26701 + ... + 26752.

2^1389778 is an apocalyptic number.

1389778 is a deficient number, since it is larger than the sum of its proper divisors (855290).

1389778 is a wasteful number, since it uses less digits than its factorization.

1389778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53468.

The product of its digits is 84672, while the sum is 43.

The square root of 1389778 is about 1178.8884595245. Note that the first 3 decimals coincide. The cubic root of 1389778 is about 111.5959612795.

The spelling of 1389778 in words is "one million, three hundred eighty-nine thousand, seven hundred seventy-eight".