11821513 has 4 divisors (see below), whose sum is σ = 12896208. Its totient is φ = 10746820.

The previous prime is 11821507. The next prime is 11821519. The reversal of 11821513 is 31512811.

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 an interprime number because it is at equal distance from previous prime (11821507) and next prime (11821519).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11821513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11821519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 537331 + ... + 537352.

It is an arithmetic number, because the mean of its divisors is an integer number (3224052).

Almost surely, 2^11821513 is an apocalyptic number.

It is an amenable number.

11821513 is a deficient number, since it is larger than the sum of its proper divisors (1074695).

11821513 is a wasteful number, since it uses less digits than its factorization.

11821513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1074694.

The product of its digits is 240, while the sum is 22.

The square root of 11821513 is about 3438.2427197625. The cubic root of 11821513 is about 227.8020815013.

It can be divided in two parts, 1182151 and 3, that multiplied together give a palindrome (3546453).

The spelling of 11821513 in words is "eleven million, eight hundred twenty-one thousand, five hundred thirteen".