18649784539 has 4 divisors (see below), whose sum is σ = 18650113024. Its totient is φ = 18649456056.

The previous prime is 18649784521. The next prime is 18649784561. The reversal of 18649784539 is 93548794681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93548794681 = 13339 ⋅7013179.

It is a 3-Lehmer number, since φ(18649784539) divides (18649784539-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18649784539 is a prime.

It is a super-2 number, since 2×18649784539² (a number of 21 digits) contains 22 as substring.

It is a deceptive number, since it divides R_18649784538.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18649784509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54747 + ... + 200740.

It is an arithmetic number, because the mean of its divisors is an integer number (4662528256).

Almost surely, 2^18649784539 is an apocalyptic number.

18649784539 is the 72997-th nonagonal number.

18649784539 is a deficient number, since it is larger than the sum of its proper divisors (328485).

18649784539 is an equidigital number, since it uses as much as digits as its factorization.

18649784539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328484.

The product of its digits is 52254720, while the sum is 64.

The spelling of 18649784539 in words is "eighteen billion, six hundred forty-nine million, seven hundred eighty-four thousand, five hundred thirty-nine".