261507 has 8 divisors (see below), whose sum is σ = 354640. Its totient is φ = 171360.

The previous prime is 261467. The next prime is 261509. The reversal of 261507 is 705162.

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

It is not a de Polignac number, because 261507 - 2⁷ = 261379 is a prime.

It is a super-2 number, since 2×261507² = 136771822098, which contains 22 as substring.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261507.

It is not an unprimeable number, because it can be changed into a prime (261509) 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, 532 + ... + 897.

It is an arithmetic number, because the mean of its divisors is an integer number (44330).

2²⁶¹⁵⁰⁷ is an apocalyptic number.

261507 is a deficient number, since it is larger than the sum of its proper divisors (93133).

261507 is a wasteful number, since it uses less digits than its factorization.

261507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1493.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 261507 is about 511.3775513258. The cubic root of 261507 is about 63.9481187614.

Adding to 261507 its reverse (705162), we get a palindrome (966669).

The spelling of 261507 in words is "two hundred sixty-one thousand, five hundred seven".