121603 has 4 divisors (see below), whose sum is σ = 122320. Its totient is φ = 120888.

The previous prime is 121591. The next prime is 121607. The reversal of 121603 is 306121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 121603 - 2⁵ = 121571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121607) 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, 58 + ... + 496.

It is an arithmetic number, because the mean of its divisors is an integer number (30580).

2¹²¹⁶⁰³ is an apocalyptic number.

121603 is a deficient number, since it is larger than the sum of its proper divisors (717).

121603 is an equidigital number, since it uses as much as digits as its factorization.

121603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 121603 is about 348.7162170017. The cubic root of 121603 is about 49.5429006037.

Adding to 121603 its reverse (306121), we get a palindrome (427724).

The spelling of 121603 in words is "one hundred twenty-one thousand, six hundred three".