801661 has 8 divisors (see below), whose sum is σ = 929664. Its totient is φ = 677040.

The previous prime is 801641. The next prime is 801677. The reversal of 801661 is 166108.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 801661 - 2¹¹ = 799613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (801611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 310 + ... + 1303.

It is an arithmetic number, because the mean of its divisors is an integer number (116208).

2⁸⁰¹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

801661 is a deficient number, since it is larger than the sum of its proper divisors (128003).

801661 is a wasteful number, since it uses less digits than its factorization.

801661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691.

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

The square root of 801661 is about 895.3552367636. The cubic root of 801661 is about 92.8959795844.

Adding to 801661 its reverse (166108), we get a palindrome (967769).

The spelling of 801661 in words is "eight hundred one thousand, six hundred sixty-one".