18661355969 has 16 divisors (see below), whose sum is σ = 20038993920. Its totient is φ = 17336713680.

The previous prime is 18661355953. The next prime is 18661356013. The reversal of 18661355969 is 96955316681.

It is not a de Polignac number, because 18661355969 - 2⁴ = 18661355953 is a prime.

It is a super-2 number, since 2×18661355969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18661354969) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75722 + ... + 207500.

It is an arithmetic number, because the mean of its divisors is an integer number (1252437120).

Almost surely, 2^18661355969 is an apocalyptic number.

It is an amenable number.

18661355969 is a deficient number, since it is larger than the sum of its proper divisors (1377637951).

18661355969 is a wasteful number, since it uses less digits than its factorization.

18661355969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131980.

The product of its digits is 10497600, while the sum is 59.

The spelling of 18661355969 in words is "eighteen billion, six hundred sixty-one million, three hundred fifty-five thousand, nine hundred sixty-nine".