816601 has 4 divisors (see below), whose sum is σ = 859600. Its totient is φ = 773604.

The previous prime is 816593. The next prime is 816649. The reversal of 816601 is 106618.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 106618 = 2 ⋅53309.

It is not a de Polignac number, because 816601 - 2³ = 816593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816691) 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, 21471 + ... + 21508.

It is an arithmetic number, because the mean of its divisors is an integer number (214900).

2⁸¹⁶⁶⁰¹ is an apocalyptic number.

It is an amenable number.

816601 is a deficient number, since it is larger than the sum of its proper divisors (42999).

816601 is a wasteful number, since it uses less digits than its factorization.

816601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42998.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 816601 is about 903.6597811123. The cubic root of 816601 is about 93.4695106819.

The spelling of 816601 in words is "eight hundred sixteen thousand, six hundred one".