18916426369 has 3 divisors (see below), whose sum is σ = 18916563907. Its totient is φ = 18916288832.

The previous prime is 18916426367. The next prime is 18916426387. The reversal of 18916426369 is 96362461981.

It is a happy number.

The square root of 18916426369 is 137537.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 16244777025 + 2671649344 = 127455^2 + 51688^2 .

It is not a de Polignac number, because 18916426369 - 2¹ = 18916426367 is a prime.

It is a super-2 number, since 2×18916426369² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18916426363) 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 2 ways as a sum of consecutive naturals, for example, 68769 + ... + 206305.

Almost surely, 2^18916426369 is an apocalyptic number.

18916426369 is the 137537-th square number.

18916426369 is the 68769-th centered octagonal number.

It is an amenable number.

18916426369 is a deficient number, since it is larger than the sum of its proper divisors (137538).

18916426369 is an frugal number, since it uses more digits than its factorization.

18916426369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275074 (or 137537 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 55.

The spelling of 18916426369 in words is "eighteen billion, nine hundred sixteen million, four hundred twenty-six thousand, three hundred sixty-nine".