18728091648 has 420 divisors, whose sum is σ = 65327271075. Its totient is φ = 5350883328.

The previous prime is 18728091637. The next prime is 18728091677. The reversal of 18728091648 is 84619082781.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 9364045824 + 9364045824 = 96768^2 + 96768^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=96768.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 18728091594 and 18728091603.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 2675441661 + ... + 2675441667.

Almost surely, 2^18728091648 is an apocalyptic number.

18728091648 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18728091648

18728091648 is an abundant number, since it is smaller than the sum of its proper divisors (46599179427).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18728091648 is an frugal number, since it uses more digits than its factorization.

18728091648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70 (or 12 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 54.

The spelling of 18728091648 in words is "eighteen billion, seven hundred twenty-eight million, ninety-one thousand, six hundred forty-eight".