1291204091520 has 2048 divisors, whose sum is σ = 5744535552000. Its totient is φ = 267544166400.

The previous prime is 1291204091519. The next prime is 1291204091533. The reversal of 1291204091520 is 251904021921.

1291204091520 is a `hidden beast` number, since 1 + 2 + 9 + 1 + 2 + 0 + 40 + 91 + 520 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 6690176544 + ... + 6690176736.

It is an arithmetic number, because the mean of its divisors is an integer number (2804949000).

Almost surely, 2^{1291204091520} is an apocalyptic number.

1291204091520 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 1291204091520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2872267776000).

1291204091520 is an abundant number, since it is smaller than the sum of its proper divisors (4453331460480).

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

1291204091520 is a wasteful number, since it uses less digits than its factorization.

1291204091520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359 (or 341 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The spelling of 1291204091520 in words is "one trillion, two hundred ninety-one billion, two hundred four million, ninety-one thousand, five hundred twenty".