261265511 has 8 divisors (see below), whose sum is σ = 286132560. Its totient is φ = 237079872.

The previous prime is 261265493. The next prime is 261265517. The reversal of 261265511 is 115562162.

It is a happy number.

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 261265511 - 2¹⁴ = 261249127 is a prime.

It is a super-2 number, since 2×261265511² = 136519334476182242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261265517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 169550 + ... + 171083.

It is an arithmetic number, because the mean of its divisors is an integer number (35766570).

Almost surely, 2^261265511 is an apocalyptic number.

261265511 is a deficient number, since it is larger than the sum of its proper divisors (24867049).

261265511 is a wasteful number, since it uses less digits than its factorization.

261265511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340705.

The product of its digits is 3600, while the sum is 29.

The square root of 261265511 is about 16163.7096917756. The cubic root of 261265511 is about 639.2842837297.

The spelling of 261265511 in words is "two hundred sixty-one million, two hundred sixty-five thousand, five hundred eleven".