1297521611905 has 4 divisors (see below), whose sum is σ = 1557025934292. Its totient is φ = 1038017289520.

The previous prime is 1297521611861. The next prime is 1297521611923. The reversal of 1297521611905 is 5091161257921.

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

It can be written as a sum of positive squares in 2 ways, for example, as 223123024881 + 1074398587024 = 472359^2 + 1036532^2 .

It is not a de Polignac number, because 1297521611905 - 2²⁵ = 1297488057473 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129752161186 + ... + 129752161195.

It is an arithmetic number, because the mean of its divisors is an integer number (389256483573).

Almost surely, 2^{1297521611905} is an apocalyptic number.

It is an amenable number.

1297521611905 is a deficient number, since it is larger than the sum of its proper divisors (259504322387).

1297521611905 is an equidigital number, since it uses as much as digits as its factorization.

1297521611905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259504322386.

The product of its (nonzero) digits is 340200, while the sum is 49.

The spelling of 1297521611905 in words is "one trillion, two hundred ninety-seven billion, five hundred twenty-one million, six hundred eleven thousand, nine hundred five".