18531799649328 has 320 divisors, whose sum is σ = 59033259343872. Its totient is φ = 4892914667520.

The previous prime is 18531799649299. The next prime is 18531799649329. The reversal of 18531799649328 is 82394699713581.

It is a self number, because there is not a number n which added to its sum of digits gives 18531799649328.

It is not an unprimeable number, because it can be changed into a prime (18531799649329) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 141998601 + ... + 142129047.

Almost surely, 2^{18531799649328} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18531799649328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29516629671936).

18531799649328 is an abundant number, since it is smaller than the sum of its proper divisors (40501459694544).

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

18531799649328 is a wasteful number, since it uses less digits than its factorization.

18531799649328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131112 (or 131106 counting only the distinct ones).

The product of its digits is 705438720, while the sum is 75.

The spelling of 18531799649328 in words is "eighteen trillion, five hundred thirty-one billion, seven hundred ninety-nine million, six hundred forty-nine thousand, three hundred twenty-eight".