261003 has 12 divisors (see below), whose sum is σ = 368808. Its totient is φ = 164160.

The previous prime is 260999. The next prime is 261011. The reversal of 261003 is 300162.

261003 is a nontrivial binomial coefficient, being equal to C(723, 2).

It is not a de Polignac number, because 261003 - 2² = 260999 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 963 + ... + 1203.

It is an arithmetic number, because the mean of its divisors is an integer number (30734).

2²⁶¹⁰⁰³ is an apocalyptic number.

261003 is the 722-nd triangular number.

261003 is a deficient number, since it is larger than the sum of its proper divisors (107805).

261003 is a wasteful number, since it uses less digits than its factorization.

261003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 261003 is about 510.8845270705. The cubic root of 261003 is about 63.9070101366.

Adding to 261003 its reverse (300162), we get a palindrome (561165).

The spelling of 261003 in words is "two hundred sixty-one thousand, three".