168391440 has 480 divisors, whose sum is σ = 709061760. Its totient is φ = 36578304.

The previous prime is 168391439. The next prime is 168391493. The reversal of 168391440 is 44193861.

168391440 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 = 168391395 and 168391404.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3916059 + ... + 3916101.

It is an arithmetic number, because the mean of its divisors is an integer number (1477212).

Almost surely, 2^168391440 is an apocalyptic number.

168391440 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 168391440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (354530880).

168391440 is an abundant number, since it is smaller than the sum of its proper divisors (540670320).

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

168391440 is a wasteful number, since it uses less digits than its factorization.

168391440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 168391440 is about 12976.5727370520. The cubic root of 168391440 is about 552.2130557524.

The spelling of 168391440 in words is "one hundred sixty-eight million, three hundred ninety-one thousand, four hundred forty".