168321640 has 32 divisors (see below), whose sum is σ = 385874280. Its totient is φ = 66057472.

The previous prime is 168321619. The next prime is 168321679. The reversal of 168321640 is 46123861.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 129458884 + 38862756 = 11378^2 + 6234^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37579 + ... + 41818.

Almost surely, 2^168321640 is an apocalyptic number.

168321640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

168321640 is an abundant number, since it is smaller than the sum of its proper divisors (217552640).

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

168321640 is a wasteful number, since it uses less digits than its factorization.

168321640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79461 (or 79457 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 168321640 is about 12973.8829962352. The cubic root of 168321640 is about 552.1367458596.

The spelling of 168321640 in words is "one hundred sixty-eight million, three hundred twenty-one thousand, six hundred forty".