1291780013 has 4 divisors (see below), whose sum is σ = 1333450368. Its totient is φ = 1250109660.

The previous prime is 1291779967. The next prime is 1291780019. The reversal of 1291780013 is 3100871921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1291780013 - 2⁶ = 1291779949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291780019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20835131 + ... + 20835192.

It is an arithmetic number, because the mean of its divisors is an integer number (333362592).

Almost surely, 2^1291780013 is an apocalyptic number.

It is an amenable number.

1291780013 is a deficient number, since it is larger than the sum of its proper divisors (41670355).

1291780013 is an equidigital number, since it uses as much as digits as its factorization.

1291780013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41670354.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 1291780013 is about 35941.3412799244. The cubic root of 1291780013 is about 1089.0877008590.

The spelling of 1291780013 in words is "one billion, two hundred ninety-one million, seven hundred eighty thousand, thirteen".