168399188 has 6 divisors (see below), whose sum is σ = 294698586. Its totient is φ = 84199592.

The previous prime is 168399139. The next prime is 168399193. The reversal of 168399188 is 881993861.

It can be written as a sum of positive squares in only one way, i.e., 164147344 + 4251844 = 12812^2 + 2062^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21049895 + ... + 21049902.

It is an arithmetic number, because the mean of its divisors is an integer number (49116431).

Almost surely, 2^168399188 is an apocalyptic number.

It is an amenable number.

168399188 is a deficient number, since it is larger than the sum of its proper divisors (126299398).

168399188 is a wasteful number, since it uses less digits than its factorization.

168399188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42099801 (or 42099799 counting only the distinct ones).

The product of its digits is 746496, while the sum is 53.

The square root of 168399188 is about 12976.8712716124. The cubic root of 168399188 is about 552.2215250688.

The spelling of 168399188 in words is "one hundred sixty-eight million, three hundred ninety-nine thousand, one hundred eighty-eight".