261216303 has 4 divisors (see below), whose sum is σ = 348288408. Its totient is φ = 174144200.

The previous prime is 261216269. The next prime is 261216331. The reversal of 261216303 is 303612162.

It is a happy number.

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 261216303 - 2²⁴ = 244439087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261216353) 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, 43536048 + ... + 43536053.

It is an arithmetic number, because the mean of its divisors is an integer number (87072102).

Almost surely, 2^261216303 is an apocalyptic number.

261216303 is a deficient number, since it is larger than the sum of its proper divisors (87072105).

261216303 is an equidigital number, since it uses as much as digits as its factorization.

261216303 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87072104.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 261216303 is about 16162.1874447737. The cubic root of 261216303 is about 639.2441459198.

Adding to 261216303 its reverse (303612162), we get a palindrome (564828465).

It can be divided in two parts, 2612 and 16303, that added together give a triangular number (18915 = T₁₉₄).

The spelling of 261216303 in words is "two hundred sixty-one million, two hundred sixteen thousand, three hundred three".