18386546409 has 81 divisors (see below), whose sum is σ = 34016257821. Its totient is φ = 9535181040.

The previous prime is 18386546407. The next prime is 18386546441. The reversal of 18386546409 is 90464568381.

The square root of 18386546409 is 135597.

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

18386546409 is a `hidden beast` number, since 18 + 3 + 86 + 546 + 4 + 0 + 9 = 666.

It is not a de Polignac number, because 18386546409 - 2¹ = 18386546407 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18386546407) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 31322614 + ... + 31323200.

Almost surely, 2^18386546409 is an apocalyptic number.

18386546409 is the 135597-th square number.

18386546409 is the 67799-th centered octagonal number.

It is an amenable number.

18386546409 is a deficient number, since it is larger than the sum of its proper divisors (15629711412).

18386546409 is an equidigital number, since it uses as much as digits as its factorization.

18386546409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216 (or 608 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 54.

The spelling of 18386546409 in words is "eighteen billion, three hundred eighty-six million, five hundred forty-six thousand, four hundred nine".