1281729913 has 8 divisors (see below), whose sum is σ = 1318674632. Its totient is φ = 1244906496.

The previous prime is 1281729893. The next prime is 1281729929. The reversal of 1281729913 is 3199271821.

It can be written as a sum of positive squares in 4 ways, for example, as 1059958249 + 221771664 = 32557^2 + 14892^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1281729913 - 2²⁹ = 744859001 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 1281729913.

It is not an unprimeable number, because it can be changed into a prime (1281729313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8670 + ... + 51367.

It is an arithmetic number, because the mean of its divisors is an integer number (164834329).

Almost surely, 2^1281729913 is an apocalyptic number.

It is an amenable number.

1281729913 is a deficient number, since it is larger than the sum of its proper divisors (36944719).

1281729913 is an equidigital number, since it uses as much as digits as its factorization.

1281729913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60651.

The product of its digits is 54432, while the sum is 43.

The square root of 1281729913 is about 35801.2557461327. The cubic root of 1281729913 is about 1086.2559625236.

The spelling of 1281729913 in words is "one billion, two hundred eighty-one million, seven hundred twenty-nine thousand, nine hundred thirteen".