1280509560 has 640 divisors, whose sum is σ = 5185382400. Its totient is φ = 279936000.

The previous prime is 1280509537. The next prime is 1280509603. The reversal of 1280509560 is 659050821.

It is a happy number.

1280509560 is a `hidden beast` number, since 12 + 80 + 5 + 0 + 9 + 560 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 20991930 + ... + 20991990.

It is an arithmetic number, because the mean of its divisors is an integer number (8102160).

Almost surely, 2^1280509560 is an apocalyptic number.

1280509560 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 1280509560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2592691200).

1280509560 is an abundant number, since it is smaller than the sum of its proper divisors (3904872840).

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

1280509560 is a wasteful number, since it uses less digits than its factorization.

1280509560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 1280509560 is about 35784.2082488910. The cubic root of 1280509560 is about 1085.9111065483.

The spelling of 1280509560 in words is "one billion, two hundred eighty million, five hundred nine thousand, five hundred sixty".