1321278208 has 18 divisors (see below), whose sum is σ = 2637395684. Its totient is φ = 660638976.

The previous prime is 1321278197. The next prime is 1321278209. The reversal of 1321278208 is 8028721231.

It is a super-2 number, since 2×1321278208² = 3491552205871382528, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1321278209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2580366 + ... + 2580877.

Almost surely, 2^1321278208 is an apocalyptic number.

It is an amenable number.

1321278208 is a deficient number, since it is larger than the sum of its proper divisors (1316117476).

1321278208 is an frugal number, since it uses more digits than its factorization.

1321278208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5161259 (or 5161245 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 1321278208 is about 36349.3907514280. The cubic root of 1321278208 is about 1097.3152732093.

Adding to 1321278208 its reverse (8028721231), we get a palindrome (9349999439).

The spelling of 1321278208 in words is "one billion, three hundred twenty-one million, two hundred seventy-eight thousand, two hundred eight".