168817819 has 4 divisors (see below), whose sum is σ = 170311896. Its totient is φ = 167323744.

The previous prime is 168817811. The next prime is 168817867. The reversal of 168817819 is 918718861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 918718861 = 2657 ⋅345773.

It is a cyclic number.

It is not a de Polignac number, because 168817819 - 2³ = 168817811 is a prime.

It is a super-2 number, since 2×168817819² = 56998912023833522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168817811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 746869 + ... + 747094.

It is an arithmetic number, because the mean of its divisors is an integer number (42577974).

Almost surely, 2^168817819 is an apocalyptic number.

168817819 is a deficient number, since it is larger than the sum of its proper divisors (1494077).

168817819 is a wasteful number, since it uses less digits than its factorization.

168817819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1494076.

The product of its digits is 193536, while the sum is 49.

The square root of 168817819 is about 12992.9911490773. The cubic root of 168817819 is about 552.6787437203.

The spelling of 168817819 in words is "one hundred sixty-eight million, eight hundred seventeen thousand, eight hundred nineteen".