1278718920 has 256 divisors, whose sum is σ = 4547404800. Its totient is φ = 318504960.

The previous prime is 1278718891. The next prime is 1278718933. The reversal of 1278718920 is 298178721.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4718385 + ... + 4718655.

It is an arithmetic number, because the mean of its divisors is an integer number (17763300).

Almost surely, 2^1278718920 is an apocalyptic number.

1278718920 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 1278718920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2273702400).

1278718920 is an abundant number, since it is smaller than the sum of its proper divisors (3268685880).

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

1278718920 is a wasteful number, since it uses less digits than its factorization.

1278718920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565 (or 555 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The square root of 1278718920 is about 35759.1795207888. The cubic root of 1278718920 is about 1085.4046980054.

The spelling of 1278718920 in words is "one billion, two hundred seventy-eight million, seven hundred eighteen thousand, nine hundred twenty".