1291420785 has 64 divisors (see below), whose sum is σ = 2257182720. Its totient is φ = 628093440.

The previous prime is 1291420751. The next prime is 1291420789. The reversal of 1291420785 is 5870241921.

It is not a de Polignac number, because 1291420785 - 2¹⁰ = 1291419761 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1291420789) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2765122 + ... + 2765588.

It is an arithmetic number, because the mean of its divisors is an integer number (35268480).

Almost surely, 2^1291420785 is an apocalyptic number.

1291420785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1291420785 is a deficient number, since it is larger than the sum of its proper divisors (965761935).

1291420785 is a wasteful number, since it uses less digits than its factorization.

1291420785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 838.

The product of its (nonzero) digits is 40320, while the sum is 39.

The square root of 1291420785 is about 35936.3435118266. The cubic root of 1291420785 is about 1088.9867375723.

The spelling of 1291420785 in words is "one billion, two hundred ninety-one million, four hundred twenty thousand, seven hundred eighty-five".