11971513 has 4 divisors (see below), whose sum is σ = 12174480. Its totient is φ = 11768548.

The previous prime is 11971499. The next prime is 11971517. The reversal of 11971513 is 31517911.

11971513 = 167² + 168² + ... + 343².

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 a de Polignac number, because none of the positive numbers 2^k-11971513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11971517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101395 + ... + 101512.

It is an arithmetic number, because the mean of its divisors is an integer number (3043620).

Almost surely, 2^11971513 is an apocalyptic number.

It is an amenable number.

11971513 is a deficient number, since it is larger than the sum of its proper divisors (202967).

11971513 is an equidigital number, since it uses as much as digits as its factorization.

11971513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202966.

The product of its digits is 945, while the sum is 28.

The square root of 11971513 is about 3459.9874277228. The cubic root of 11971513 is about 228.7615412175.

The spelling of 11971513 in words is "eleven million, nine hundred seventy-one thousand, five hundred thirteen".