1378816 has 20 divisors (see below), whose sum is σ = 2755962. Its totient is φ = 689152.

The previous prime is 1378813. The next prime is 1378823. The reversal of 1378816 is 6188731.

It can be written as a sum of positive squares in only one way, i.e., 1218816 + 160000 = 1104^2 + 400^2 .

It is a super-2 number, since 2×1378816² = 3802267123712, which contains 22 as substring.

It is a zygodrome in base 4.

It is not an unprimeable number, because it can be changed into a prime (1378813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 835 + ... + 1858.

2^1378816 is an apocalyptic number.

1378816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1378816 is a deficient number, since it is larger than the sum of its proper divisors (1377146).

1378816 is an frugal number, since it uses more digits than its factorization.

1378816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2711 (or 2695 counting only the distinct ones).

The product of its digits is 8064, while the sum is 34.

The square root of 1378816 is about 1174.2299604422. The cubic root of 1378816 is about 111.3017786998.

The spelling of 1378816 in words is "one million, three hundred seventy-eight thousand, eight hundred sixteen".