303661 has 4 divisors (see below), whose sum is σ = 305824. Its totient is φ = 301500.

The previous prime is 303649. The next prime is 303679. The reversal of 303661 is 166303.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 303661 - 2¹⁷ = 172589 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 (303691) 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, 855 + ... + 1156.

It is an arithmetic number, because the mean of its divisors is an integer number (76456).

2³⁰³⁶⁶¹ is an apocalyptic number.

It is an amenable number.

303661 is a deficient number, since it is larger than the sum of its proper divisors (2163).

303661 is a wasteful number, since it uses less digits than its factorization.

303661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2162.

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

The square root of 303661 is about 551.0544437712. The cubic root of 303661 is about 67.2145052069.

Adding to 303661 its reverse (166303), we get a palindrome (469964).

The spelling of 303661 in words is "three hundred three thousand, six hundred sixty-one".