11651813 has 4 divisors (see below), whose sum is σ = 11668320. Its totient is φ = 11635308.

The previous prime is 11651797. The next prime is 11651819. The reversal of 11651813 is 31815611.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31815611 = 311 ⋅102301.

It is a cyclic number.

It is not a de Polignac number, because 11651813 - 2⁴ = 11651797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11651819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7145 + ... + 8622.

It is an arithmetic number, because the mean of its divisors is an integer number (2917080).

Almost surely, 2^11651813 is an apocalyptic number.

It is an amenable number.

11651813 is a deficient number, since it is larger than the sum of its proper divisors (16507).

11651813 is an equidigital number, since it uses as much as digits as its factorization.

11651813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16506.

The product of its digits is 720, while the sum is 26.

The square root of 11651813 is about 3413.4752086400. The cubic root of 11651813 is about 226.7067765909.

The spelling of 11651813 in words is "eleven million, six hundred fifty-one thousand, eight hundred thirteen".