18155493440 has 448 divisors, whose sum is σ = 53880837120. Its totient is φ = 5693276160.

The previous prime is 18155493373. The next prime is 18155493533. The reversal of 18155493440 is 4439455181.

It is a tau number, because it is divible by the number of its divisors (448).

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18155493391 and 18155493400.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 166564106 + ... + 166564214.

Almost surely, 2^18155493440 is an apocalyptic number.

18155493440 is a gapful number since it is divisible by the number (10) 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 18155493440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26940418560).

18155493440 is an abundant number, since it is smaller than the sum of its proper divisors (35725343680).

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

18155493440 is a wasteful number, since it uses less digits than its factorization.

18155493440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270 (or 260 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 44.

The spelling of 18155493440 in words is "eighteen billion, one hundred fifty-five million, four hundred ninety-three thousand, four hundred forty".