11666818511 has 4 divisors (see below), whose sum is σ = 11672622024. Its totient is φ = 11661015000.

The previous prime is 11666818469. The next prime is 11666818543. The reversal of 11666818511 is 11581866611.

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

It is a cyclic number.

It is not a de Polignac number, because 11666818511 - 2⁶ = 11666818447 is a prime.

It is a super-2 number, since 2×11666818511² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11666518511) 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, 2898740 + ... + 2902761.

It is an arithmetic number, because the mean of its divisors is an integer number (2918155506).

Almost surely, 2^11666818511 is an apocalyptic number.

11666818511 is a deficient number, since it is larger than the sum of its proper divisors (5803513).

11666818511 is an equidigital number, since it uses as much as digits as its factorization.

11666818511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5803512.

The product of its digits is 69120, while the sum is 44.

The spelling of 11666818511 in words is "eleven billion, six hundred sixty-six million, eight hundred eighteen thousand, five hundred eleven".