261505063 has 8 divisors (see below), whose sum is σ = 262984176. Its totient is φ = 260030400.

The previous prime is 261505043. The next prime is 261505117. The reversal of 261505063 is 360505162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261505063 - 2¹⁷ = 261373991 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 (261505043) 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 7 ways as a sum of consecutive naturals, for example, 239148 + ... + 240238.

It is an arithmetic number, because the mean of its divisors is an integer number (32873022).

Almost surely, 2^261505063 is an apocalyptic number.

261505063 is a deficient number, since it is larger than the sum of its proper divisors (1479113).

261505063 is a wasteful number, since it uses less digits than its factorization.

261505063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2225.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 261505063 is about 16171.1181740781. The cubic root of 261505063 is about 639.4796087169.

Subtracting 261505063 from its reverse (360505162), we obtain a palindrome (99000099).

It can be divided in two parts, 26150 and 5063, that added together give a palindrome (31213).

The spelling of 261505063 in words is "two hundred sixty-one million, five hundred five thousand, sixty-three".