18385656404 has 24 divisors (see below), whose sum is σ = 32979310056. Its totient is φ = 8963264000.

The previous prime is 18385656391. The next prime is 18385656407. The reversal of 18385656404 is 40465658381.

It can be written as a sum of positive squares in 4 ways, for example, as 4691976004 + 13693680400 = 68498^2 + 117020^2 .

It is a super-2 number, since 2×18385656404² (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 (18385656407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 249674 + ... + 314814.

It is an arithmetic number, because the mean of its divisors is an integer number (1374137919).

Almost surely, 2^18385656404 is an apocalyptic number.

It is an amenable number.

18385656404 is a deficient number, since it is larger than the sum of its proper divisors (14593653652).

18385656404 is a wasteful number, since it uses less digits than its factorization.

18385656404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66907 (or 66905 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 50.

The spelling of 18385656404 in words is "eighteen billion, three hundred eighty-five million, six hundred fifty-six thousand, four hundred four".