1278520320 has 704 divisors, whose sum is σ = 5433163776. Its totient is φ = 248709120.

The previous prime is 1278520267. The next prime is 1278520339. The reversal of 1278520320 is 230258721.

It is a tau number, because it is divible by the number of its divisors (704).

It is a super-4 number, since 4×1278520320⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 27202537 + ... + 27202583.

Almost surely, 2^1278520320 is an apocalyptic number.

1278520320 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 1278520320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2716581888).

1278520320 is an abundant number, since it is smaller than the sum of its proper divisors (4154643456).

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

1278520320 is a wasteful number, since it uses less digits than its factorization.

1278520320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 98 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 1278520320 is about 35756.4025036077. The cubic root of 1278520320 is about 1085.3485030824.

The spelling of 1278520320 in words is "one billion, two hundred seventy-eight million, five hundred twenty thousand, three hundred twenty".