661803 has 8 divisors (see below), whose sum is σ = 897600. Its totient is φ = 433608.

The previous prime is 661777. The next prime is 661823. The reversal of 661803 is 308166.

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

It is not a de Polignac number, because 661803 - 2⁸ = 661547 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1693 + ... + 2046.

It is an arithmetic number, because the mean of its divisors is an integer number (112200).

2⁶⁶¹⁸⁰³ is an apocalyptic number.

661803 is a deficient number, since it is larger than the sum of its proper divisors (235797).

661803 is a wasteful number, since it uses less digits than its factorization.

661803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3801.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 661803 is about 813.5127534341. The cubic root of 661803 is about 87.1450875410.

Adding to 661803 its reverse (308166), we get a palindrome (969969).

The spelling of 661803 in words is "six hundred sixty-one thousand, eight hundred three".