1281978328 has 8 divisors (see below), whose sum is σ = 2403709380. Its totient is φ = 640989160.

The previous prime is 1281978323. The next prime is 1281978367. The reversal of 1281978328 is 8238791821.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281978323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80123638 + ... + 80123653.

Almost surely, 2^1281978328 is an apocalyptic number.

It is an amenable number.

1281978328 is a deficient number, since it is larger than the sum of its proper divisors (1121731052).

1281978328 is a wasteful number, since it uses less digits than its factorization.

1281978328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160247297 (or 160247293 counting only the distinct ones).

The product of its digits is 387072, while the sum is 49.

The square root of 1281978328 is about 35804.7249395942. The cubic root of 1281978328 is about 1086.3261345729.

The spelling of 1281978328 in words is "one billion, two hundred eighty-one million, nine hundred seventy-eight thousand, three hundred twenty-eight".