661303 has 4 divisors (see below), whose sum is σ = 667480. Its totient is φ = 655128.

The previous prime is 661267. The next prime is 661321. The reversal of 661303 is 303166.

It is a happy number.

661303 is nontrivially palindromic in base 9.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 661303 - 2⁹ = 660791 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 (661343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2925 + ... + 3142.

It is an arithmetic number, because the mean of its divisors is an integer number (166870).

2⁶⁶¹³⁰³ is an apocalyptic number.

661303 is a deficient number, since it is larger than the sum of its proper divisors (6177).

661303 is a wasteful number, since it uses less digits than its factorization.

661303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6176.

The product of its (nonzero) digits is 324, while the sum is 19.

The square root of 661303 is about 813.2053861110. The cubic root of 661303 is about 87.1231356300.

Adding to 661303 its reverse (303166), we get a palindrome (964469).

It can be divided in two parts, 66 and 1303, that added together give a square (1369 = 37²).

The spelling of 661303 in words is "six hundred sixty-one thousand, three hundred three".