1278566400 has 168 divisors, whose sum is σ = 4229566344. Its totient is φ = 340787200.

The previous prime is 1278566357. The next prime is 1278566407. The reversal of 1278566400 is 46658721.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278566407) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 613360 + ... + 615440.

Almost surely, 2^1278566400 is an apocalyptic number.

1278566400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1278566400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2114783172).

1278566400 is an abundant number, since it is smaller than the sum of its proper divisors (2950999944).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1278566400 is an equidigital number, since it uses as much as digits as its factorization.

1278566400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2120 (or 2091 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 1278566400 is about 35757.0468579272. The cubic root of 1278566400 is about 1085.3615421812.

The spelling of 1278566400 in words is "one billion, two hundred seventy-eight million, five hundred sixty-six thousand, four hundred".