18640144647 has 12 divisors (see below), whose sum is σ = 26929596720. Its totient is φ = 12424481568.

The previous prime is 18640144639. The next prime is 18640144703. The reversal of 18640144647 is 74644104681.

18640144647 is a `hidden beast` number, since 186 + 4 + 0 + 1 + 4 + 464 + 7 = 666.

It is not a de Polignac number, because 18640144647 - 2³ = 18640144639 is a prime.

It is a super-2 number, since 2×18640144647² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640146647) 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 11 ways as a sum of consecutive naturals, for example, 137622 + ... + 237107.

It is an arithmetic number, because the mean of its divisors is an integer number (2244133060).

Almost surely, 2^18640144647 is an apocalyptic number.

18640144647 is a deficient number, since it is larger than the sum of its proper divisors (8289452073).

18640144647 is a wasteful number, since it uses less digits than its factorization.

18640144647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380262 (or 380259 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 45.

The spelling of 18640144647 in words is "eighteen billion, six hundred forty million, one hundred forty-four thousand, six hundred forty-seven".