1291256415 has 12 divisors (see below), whose sum is σ = 2238177864. Its totient is φ = 688670064.

The previous prime is 1291256347. The next prime is 1291256441. The reversal of 1291256415 is 5146521921.

1291256415 is a `hidden beast` number, since 1 + 2 + 9 + 1 + 2 + 5 + 641 + 5 = 666.

It is not a de Polignac number, because 1291256415 - 2⁷ = 1291256287 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1291256415.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 14347249 + ... + 14347338.

It is an arithmetic number, because the mean of its divisors is an integer number (186514822).

Almost surely, 2^1291256415 is an apocalyptic number.

1291256415 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1291256415 is a deficient number, since it is larger than the sum of its proper divisors (946921449).

1291256415 is a wasteful number, since it uses less digits than its factorization.

1291256415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28694598 (or 28694595 counting only the distinct ones).

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

The square root of 1291256415 is about 35934.0564784996. The cubic root of 1291256415 is about 1088.9405341074.

The spelling of 1291256415 in words is "one billion, two hundred ninety-one million, two hundred fifty-six thousand, four hundred fifteen".