819668 has 6 divisors (see below), whose sum is σ = 1434426. Its totient is φ = 409832.

The previous prime is 819659. The next prime is 819673. The reversal of 819668 is 866918.

It can be written as a sum of positive squares in only one way, i.e., 669124 + 150544 = 818^2 + 388^2 .

It is a super-3 number, since 3×819668³ = 1652095682143336896, which contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

819668 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102455 + ... + 102462.

It is an arithmetic number, because the mean of its divisors is an integer number (239071).

2⁸¹⁹⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

819668 is a deficient number, since it is larger than the sum of its proper divisors (614758).

819668 is a wasteful number, since it uses less digits than its factorization.

819668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204921 (or 204919 counting only the distinct ones).

The product of its digits is 20736, while the sum is 38.

The square root of 819668 is about 905.3551789215. The cubic root of 819668 is about 93.5863824639.

The spelling of 819668 in words is "eight hundred nineteen thousand, six hundred sixty-eight".