1291302991 has 4 divisors (see below), whose sum is σ = 1408694184. Its totient is φ = 1173911800.

The previous prime is 1291302979. The next prime is 1291303001. The reversal of 1291302991 is 1992031921.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1291302991 - 2¹⁷ = 1291171919 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1291302991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291302941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58695580 + ... + 58695601.

It is an arithmetic number, because the mean of its divisors is an integer number (352173546).

Almost surely, 2^1291302991 is an apocalyptic number.

1291302991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1291302991 is a deficient number, since it is larger than the sum of its proper divisors (117391193).

1291302991 is a wasteful number, since it uses less digits than its factorization.

1291302991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117391192.

The product of its (nonzero) digits is 8748, while the sum is 37.

The square root of 1291302991 is about 35934.7045486672. The cubic root of 1291302991 is about 1088.9536267521.

The spelling of 1291302991 in words is "one billion, two hundred ninety-one million, three hundred two thousand, nine hundred ninety-one".