1291880205 has 256 divisors, whose sum is σ = 3126067200. Its totient is φ = 489888000.

The previous prime is 1291880203. The next prime is 1291880209. The reversal of 1291880205 is 5020881921.

It is not a de Polignac number, because 1291880205 - 2¹ = 1291880203 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1291880205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291880203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 6122550 + ... + 6122760.

It is an arithmetic number, because the mean of its divisors is an integer number (12211200).

Almost surely, 2^1291880205 is an apocalyptic number.

1291880205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1291880205 is an abundant number, since it is smaller than the sum of its proper divisors (1834186995).

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

1291880205 is a wasteful number, since it uses less digits than its factorization.

1291880205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293 (or 287 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 1291880205 is about 35942.7350795679. The cubic root of 1291880205 is about 1089.1158571119.

The spelling of 1291880205 in words is "one billion, two hundred ninety-one million, eight hundred eighty thousand, two hundred five".