168821904 has 80 divisors (see below), whose sum is σ = 446221440. Its totient is φ = 54988800.

The previous prime is 168821903. The next prime is 168821911. The reversal of 168821904 is 409128861.

It is not an unprimeable number, because it can be changed into a prime (168821903) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 470077 + ... + 470435.

It is an arithmetic number, because the mean of its divisors is an integer number (5577768).

Almost surely, 2^168821904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 168821904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (223110720).

168821904 is an abundant number, since it is smaller than the sum of its proper divisors (277399536).

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

168821904 is a wasteful number, since it uses less digits than its factorization.

168821904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568 (or 562 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 168821904 is about 12993.1483482642. The cubic root of 168821904 is about 552.6832015326.

The spelling of 168821904 in words is "one hundred sixty-eight million, eight hundred twenty-one thousand, nine hundred four".