168661440 has 224 divisors, whose sum is σ = 604845120. Its totient is φ = 44789760.

The previous prime is 168661417. The next prime is 168661459. The reversal of 168661440 is 44166861.

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 = 168661395 and 168661404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 699720 + ... + 699960.

Almost surely, 2^168661440 is an apocalyptic number.

168661440 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 168661440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (302422560).

168661440 is an abundant number, since it is smaller than the sum of its proper divisors (436183680).

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

168661440 is an frugal number, since it uses more digits than its factorization.

168661440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 168661440 is about 12986.9719334416. The cubic root of 168661440 is about 552.5080388940.

The spelling of 168661440 in words is "one hundred sixty-eight million, six hundred sixty-one thousand, four hundred forty".