1278247808 has 64 divisors (see below), whose sum is σ = 2611526400. Its totient is φ = 623021568.

The previous prime is 1278247807. The next prime is 1278247837. The reversal of 1278247808 is 8087428721.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278247807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 838535 + ... + 840057.

It is an arithmetic number, because the mean of its divisors is an integer number (40805100).

Almost surely, 2^1278247808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1278247808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1305763200).

1278247808 is an abundant number, since it is smaller than the sum of its proper divisors (1333278592).

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

1278247808 is an equidigital number, since it uses as much as digits as its factorization.

1278247808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1699 (or 1687 counting only the distinct ones).

The product of its (nonzero) digits is 401408, while the sum is 47.

The square root of 1278247808 is about 35752.5916263423. The cubic root of 1278247808 is about 1085.2713848953.

The spelling of 1278247808 in words is "one billion, two hundred seventy-eight million, two hundred forty-seven thousand, eight hundred eight".