18690444369 has 27 divisors (see below), whose sum is σ = 27252660123. Its totient is φ = 12343543344.

The previous prime is 18690444361. The next prime is 18690444413. The reversal of 18690444369 is 96344409681.

It is a happy number.

The square root of 18690444369 is 136713.

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

18690444369 is a `hidden beast` number, since 1 + 86 + 90 + 44 + 436 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17407371969 + 1283072400 = 131937^2 + 35820^2 .

It is not a de Polignac number, because 18690444369 - 2³ = 18690444361 is a prime.

It is a super-2 number, since 2×18690444369² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18690444361) 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 26 ways as a sum of consecutive naturals, for example, 81617547 + ... + 81617775.

Almost surely, 2^18690444369 is an apocalyptic number.

18690444369 is the 136713-rd square number.

18690444369 is the 68357-th centered octagonal number.

It is an amenable number.

18690444369 is a deficient number, since it is larger than the sum of its proper divisors (8562215754).

18690444369 is an frugal number, since it uses more digits than its factorization.

18690444369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862 (or 431 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 54.

The spelling of 18690444369 in words is "eighteen billion, six hundred ninety million, four hundred forty-four thousand, three hundred sixty-nine".