261113505 has 16 divisors (see below), whose sum is σ = 423667584. Its totient is φ = 137298560.

The previous prime is 261113497. The next prime is 261113513. The reversal of 261113505 is 505311162.

It is an interprime number because it is at equal distance from previous prime (261113497) and next prime (261113513).

It is not a de Polignac number, because 261113505 - 2³ = 261113497 is a prime.

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, 121524 + ... + 123653.

It is an arithmetic number, because the mean of its divisors is an integer number (26479224).

Almost surely, 2^261113505 is an apocalyptic number.

It is an amenable number.

261113505 is a deficient number, since it is larger than the sum of its proper divisors (162554079).

261113505 is a wasteful number, since it uses less digits than its factorization.

261113505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245256.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 261113505 is about 16159.0069311205. The cubic root of 261113505 is about 639.1602797382.

Adding to 261113505 its reverse (505311162), we get a palindrome (766424667).

The spelling of 261113505 in words is "two hundred sixty-one million, one hundred thirteen thousand, five hundred five".