1291749440 has 28 divisors (see below), whose sum is σ = 3075979116. Its totient is φ = 516699648.

The previous prime is 1291749427. The next prime is 1291749451. The reversal of 1291749440 is 449471921.

It can be written as a sum of positive squares in 2 ways, for example, as 662341696 + 629407744 = 25736^2 + 25088^2 .

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2018039 + ... + 2018678.

It is an arithmetic number, because the mean of its divisors is an integer number (109856397).

Almost surely, 2^1291749440 is an apocalyptic number.

1291749440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1291749440 is an abundant number, since it is smaller than the sum of its proper divisors (1784229676).

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

1291749440 is an equidigital number, since it uses as much as digits as its factorization.

1291749440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4036734 (or 4036724 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 1291749440 is about 35940.9159593909. The cubic root of 1291749440 is about 1089.0791088541.

The spelling of 1291749440 in words is "one billion, two hundred ninety-one million, seven hundred forty-nine thousand, four hundred forty".