11815172513 has 2 divisors, whose sum is σ = 11815172514. Its totient is φ = 11815172512.

The previous prime is 11815172497. The next prime is 11815172543. The reversal of 11815172513 is 31527151811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11208880384 + 606292129 = 105872^2 + 24623^2 .

It is a cyclic number.

It is not a de Polignac number, because 11815172513 - 2⁴ = 11815172497 is a prime.

It is not a weakly prime, because it can be changed into another prime (11815172543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5907586256 + 5907586257.

It is an arithmetic number, because the mean of its divisors is an integer number (5907586257).

Almost surely, 2^11815172513 is an apocalyptic number.

It is an amenable number.

11815172513 is a deficient number, since it is larger than the sum of its proper divisors (1).

11815172513 is an equidigital number, since it uses as much as digits as its factorization.

11815172513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8400, while the sum is 35.

The spelling of 11815172513 in words is "eleven billion, eight hundred fifteen million, one hundred seventy-two thousand, five hundred thirteen".