1287780520 has 64 divisors (see below), whose sum is σ = 3127662720. Its totient is φ = 474380544.

The previous prime is 1287780509. The next prime is 1287780547. The reversal of 1287780520 is 250877821.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 240189 + ... + 245491.

It is an arithmetic number, because the mean of its divisors is an integer number (48869730).

Almost surely, 2^1287780520 is an apocalyptic number.

1287780520 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 1287780520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1563831360).

1287780520 is an abundant number, since it is smaller than the sum of its proper divisors (1839882200).

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

1287780520 is a wasteful number, since it uses less digits than its factorization.

1287780520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5794 (or 5790 counting only the distinct ones).

The product of its (nonzero) digits is 62720, while the sum is 40.

The square root of 1287780520 is about 35885.6589740247. The cubic root of 1287780520 is about 1087.9625604367.

The spelling of 1287780520 in words is "one billion, two hundred eighty-seven million, seven hundred eighty thousand, five hundred twenty".