168391840 has 48 divisors (see below), whose sum is σ = 401006592. Its totient is φ = 66818304.

The previous prime is 168391829. The next prime is 168391849. The reversal of 168391840 is 48193861.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 168391793 and 168391802.

It is not an unprimeable number, because it can be changed into a prime (168391849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16177 + ... + 24463.

It is an arithmetic number, because the mean of its divisors is an integer number (8354304).

Almost surely, 2^168391840 is an apocalyptic number.

168391840 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 168391840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (200503296).

168391840 is an abundant number, since it is smaller than the sum of its proper divisors (232614752).

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

168391840 is a wasteful number, since it uses less digits than its factorization.

168391840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8429 (or 8421 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 168391840 is about 12976.5881494328. The cubic root of 168391840 is about 552.2134929976.

The spelling of 168391840 in words is "one hundred sixty-eight million, three hundred ninety-one thousand, eight hundred forty".