11581921669 has 2 divisors, whose sum is σ = 11581921670. Its totient is φ = 11581921668.

The previous prime is 11581921657. The next prime is 11581921679. The reversal of 11581921669 is 96612918511.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6567157444 + 5014764225 = 81038^2 + 70815^2 .

It is an emirp because it is prime and its reverse (96612918511) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11581921669 - 2⁹ = 11581921157 is a prime.

It is a super-2 number, since 2×11581921669² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11581921679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5790960834 + 5790960835.

It is an arithmetic number, because the mean of its divisors is an integer number (5790960835).

Almost surely, 2^11581921669 is an apocalyptic number.

It is an amenable number.

11581921669 is a deficient number, since it is larger than the sum of its proper divisors (1).

11581921669 is an equidigital number, since it uses as much as digits as its factorization.

11581921669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 49.

The spelling of 11581921669 in words is "eleven billion, five hundred eighty-one million, nine hundred twenty-one thousand, six hundred sixty-nine".