18168373440 has 896 divisors, whose sum is σ = 78723256320. Its totient is φ = 3853910016.

The previous prime is 18168373429. The next prime is 18168373499. The reversal of 18168373440 is 4437386181.

18168373440 is a `hidden beast` number, since 1 + 81 + 68 + 3 + 73 + 440 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 51468304 + ... + 51468656.

Almost surely, 2^18168373440 is an apocalyptic number.

18168373440 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 18168373440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39361628160).

18168373440 is an abundant number, since it is smaller than the sum of its proper divisors (60554882880).

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

18168373440 is a wasteful number, since it uses less digits than its factorization.

18168373440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446 (or 430 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 18168373440 in words is "eighteen billion, one hundred sixty-eight million, three hundred seventy-three thousand, four hundred forty".