1291079856 has 80 divisors (see below), whose sum is σ = 3646695168. Its totient is φ = 390355200.

The previous prime is 1291079851. The next prime is 1291079863. The reversal of 1291079856 is 6589701921.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (1291079851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 254626 + ... + 259646.

Almost surely, 2^1291079856 is an apocalyptic number.

1291079856 is a gapful number since it is divisible by the number (16) 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 1291079856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1823347584).

1291079856 is an abundant number, since it is smaller than the sum of its proper divisors (2355615312).

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

1291079856 is a wasteful number, since it uses less digits than its factorization.

1291079856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5530 (or 5524 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 48.

The square root of 1291079856 is about 35931.5996860702. The cubic root of 1291079856 is about 1088.8909000163.

The spelling of 1291079856 in words is "one billion, two hundred ninety-one million, seventy-nine thousand, eight hundred fifty-six".