1291782080520 has 512 divisors, whose sum is σ = 4443090624000. Its totient is φ = 337884991488.

The previous prime is 1291782080471. The next prime is 1291782080521. The reversal of 1291782080520 is 250802871921.

1291782080520 is a `hidden beast` number, since 1 + 29 + 1 + 7 + 8 + 20 + 80 + 520 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (1291782080521) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2537882026 + ... + 2537882534.

It is an arithmetic number, because the mean of its divisors is an integer number (8677911375).

Almost surely, 2^{1291782080520} is an apocalyptic number.

1291782080520 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 1291782080520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2221545312000).

1291782080520 is an abundant number, since it is smaller than the sum of its proper divisors (3151308543480).

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

1291782080520 is an equidigital number, since it uses as much as digits as its factorization.

1291782080520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041 (or 1019 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 1291782080520 in words is "one trillion, two hundred ninety-one billion, seven hundred eighty-two million, eighty thousand, five hundred twenty".