1278558720 has 240 divisors, whose sum is σ = 4465910592. Its totient is φ = 338042880.

The previous prime is 1278558703. The next prime is 1278558739. The reversal of 1278558720 is 278558721.

1278558720 is a `hidden beast` number, since 1 + 2 + 78 + 558 + 7 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4861309 + ... + 4861571.

Almost surely, 2^1278558720 is an apocalyptic number.

1278558720 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 1278558720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2232955296).

1278558720 is an abundant number, since it is smaller than the sum of its proper divisors (3187351872).

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

1278558720 is a wasteful number, since it uses less digits than its factorization.

1278558720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503 (or 484 counting only the distinct ones).

The product of its (nonzero) digits is 313600, while the sum is 45.

The square root of 1278558720 is about 35756.9394663469. The cubic root of 1278558720 is about 1085.3593690198.

Subtracting from 1278558720 its reverse (278558721), we obtain a palindrome (999999999).

The spelling of 1278558720 in words is "one billion, two hundred seventy-eight million, five hundred fifty-eight thousand, seven hundred twenty".