168720040 has 16 divisors (see below), whose sum is σ = 379620180. Its totient is φ = 67488000.

The previous prime is 168720029. The next prime is 168720049. The reversal of 168720040 is 40027861.

It can be written as a sum of positive squares in 2 ways, for example, as 158105476 + 10614564 = 12574^2 + 3258^2 .

It is a junction number, because it is equal to n+sod(n) for n = 168719990 and 168720008.

It is not an unprimeable number, because it can be changed into a prime (168720049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2108961 + ... + 2109040.

Almost surely, 2^168720040 is an apocalyptic number.

168720040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

168720040 is an abundant number, since it is smaller than the sum of its proper divisors (210900140).

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

168720040 is a wasteful number, since it uses less digits than its factorization.

168720040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4218012 (or 4218008 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 168720040 is about 12989.2278446411. The cubic root of 168720040 is about 552.5720195764.

The spelling of 168720040 in words is "one hundred sixty-eight million, seven hundred twenty thousand, forty".