261530315 has 4 divisors (see below), whose sum is σ = 313836384. Its totient is φ = 209224248.

The previous prime is 261530293. The next prime is 261530317. The reversal of 261530315 is 513035162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 513035162 = 2 ⋅256517581.

It is a cyclic number.

It is not a de Polignac number, because 261530315 - 2²² = 257336011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261530317) 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, 26153027 + ... + 26153036.

It is an arithmetic number, because the mean of its divisors is an integer number (78459096).

Almost surely, 2^261530315 is an apocalyptic number.

261530315 is a deficient number, since it is larger than the sum of its proper divisors (52306069).

261530315 is an equidigital number, since it uses as much as digits as its factorization.

261530315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52306068.

The product of its (nonzero) digits is 2700, while the sum is 26.

The square root of 261530315 is about 16171.8989299340. The cubic root of 261530315 is about 639.5001916445.

Adding to 261530315 its reverse (513035162), we get a palindrome (774565477).

The spelling of 261530315 in words is "two hundred sixty-one million, five hundred thirty thousand, three hundred fifteen".