168218640 has 160 divisors (see below), whose sum is σ = 592104960. Its totient is φ = 43877376.

The previous prime is 168218639. The next prime is 168218641. The reversal of 168218640 is 46812861.

168218640 is a `hidden beast` number, since 1 + 6 + 8 + 2 + 1 + 8 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (168218639) and next prime (168218641).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 168218595 and 168218604.

It is not an unprimeable number, because it can be changed into a prime (168218641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 100692 + ... + 102348.

It is an arithmetic number, because the mean of its divisors is an integer number (3700656).

Almost surely, 2^168218640 is an apocalyptic number.

168218640 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 168218640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (296052480).

168218640 is an abundant number, since it is smaller than the sum of its proper divisors (423886320).

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

168218640 is a wasteful number, since it uses less digits than its factorization.

168218640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1726 (or 1714 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 168218640 is about 12969.9128755748. The cubic root of 168218640 is about 552.0241010271.

The spelling of 168218640 in words is "one hundred sixty-eight million, two hundred eighteen thousand, six hundred forty".