261520415 has 16 divisors (see below), whose sum is σ = 342249600. Its totient is φ = 190674432.

The previous prime is 261520387. The next prime is 261520423. The reversal of 261520415 is 514025162.

It is not a de Polignac number, because 261520415 - 2⁸ = 261520159 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20330 + ... + 30599.

It is an arithmetic number, because the mean of its divisors is an integer number (21390600).

Almost surely, 2^261520415 is an apocalyptic number.

261520415 is a deficient number, since it is larger than the sum of its proper divisors (80729185).

261520415 is a wasteful number, since it uses less digits than its factorization.

261520415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51026.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 261520415 is about 16171.5928405337. The cubic root of 261520415 is about 639.4921223036.

Adding to 261520415 its reverse (514025162), we get a palindrome (775545577).

The spelling of 261520415 in words is "two hundred sixty-one million, five hundred twenty thousand, four hundred fifteen".