18549540408640 has 28 divisors (see below), whose sum is σ = 44171093098836. Its totient is φ = 7419816163328.

The previous prime is 18549540408629. The next prime is 18549540408647. The reversal of 18549540408640 is 4680404594581.

It can be written as a sum of positive squares in 2 ways, for example, as 4531585077504 + 14017955331136 = 2128752^2 + 3744056^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18549540408647) 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, 28983656569 + ... + 28983657208.

Almost surely, 2^{18549540408640} is an apocalyptic number.

18549540408640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18549540408640 is an abundant number, since it is smaller than the sum of its proper divisors (25621552690196).

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

18549540408640 is an equidigital number, since it uses as much as digits as its factorization.

18549540408640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57967313794 (or 57967313784 counting only the distinct ones).

The product of its (nonzero) digits is 22118400, while the sum is 58.

The spelling of 18549540408640 in words is "eighteen trillion, five hundred forty-nine billion, five hundred forty million, four hundred eight thousand, six hundred forty".