18918992669 has 4 divisors (see below), whose sum is σ = 19057087644. Its totient is φ = 18780897696.

The previous prime is 18918992633. The next prime is 18918992671. The reversal of 18918992669 is 96629981981.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16611343225 + 2307649444 = 128885^2 + 48038^2 .

It is a cyclic number.

It is not a de Polignac number, because 18918992669 - 2²⁰ = 18917944093 is a prime.

It is a super-2 number, since 2×18918992669² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18918992599 and 18918992608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18918992689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69047282 + ... + 69047555.

It is an arithmetic number, because the mean of its divisors is an integer number (4764271911).

Almost surely, 2^18918992669 is an apocalyptic number.

It is an amenable number.

18918992669 is a deficient number, since it is larger than the sum of its proper divisors (138094975).

18918992669 is a wasteful number, since it uses less digits than its factorization.

18918992669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138094974.

The product of its digits is 30233088, while the sum is 68.

The spelling of 18918992669 in words is "eighteen billion, nine hundred eighteen million, nine hundred ninety-two thousand, six hundred sixty-nine".