603661 has 4 divisors (see below), whose sum is σ = 606592. Its totient is φ = 600732.

The previous prime is 603641. The next prime is 603667. The reversal of 603661 is 166306.

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 603661 - 2⁹ = 603149 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 (603667) 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, 1131 + ... + 1576.

It is an arithmetic number, because the mean of its divisors is an integer number (151648).

2⁶⁰³⁶⁶¹ is an apocalyptic number.

It is an amenable number.

603661 is a deficient number, since it is larger than the sum of its proper divisors (2931).

603661 is a wasteful number, since it uses less digits than its factorization.

603661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2930.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 603661 is about 776.9562407240. The cubic root of 603661 is about 84.5144636376.

Adding to 603661 its reverse (166306), we get a palindrome (769967).

It can be divided in two parts, 60 and 3661, that added together give a square (3721 = 61²).

The spelling of 603661 in words is "six hundred three thousand, six hundred sixty-one".