261907 has 4 divisors (see below), whose sum is σ = 263536. Its totient is φ = 260280.

The previous prime is 261887. The next prime is 261917. The reversal of 261907 is 709162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 709162 = 2 ⋅354581.

It is a cyclic number.

It is not a de Polignac number, because 261907 - 2¹⁵ = 229139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 543 + ... + 904.

It is an arithmetic number, because the mean of its divisors is an integer number (65884).

2²⁶¹⁹⁰⁷ is an apocalyptic number.

261907 is a deficient number, since it is larger than the sum of its proper divisors (1629).

261907 is a wasteful number, since it uses less digits than its factorization.

261907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1628.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 261907 is about 511.7685023524. The cubic root of 261907 is about 63.9807070753.

The spelling of 261907 in words is "two hundred sixty-one thousand, nine hundred seven".