261906 has 8 divisors (see below), whose sum is σ = 523824. Its totient is φ = 87300.

The previous prime is 261887. The next prime is 261917. The reversal of 261906 is 609162.

261906 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

261906 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a nialpdrome in base 8.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21820 + ... + 21831.

It is an arithmetic number, because the mean of its divisors is an integer number (65478).

2²⁶¹⁹⁰⁶ is an apocalyptic number.

261906 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261906 is a wasteful number, since it uses less digits than its factorization.

261906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43656.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 261906 is about 511.7675253472. The cubic root of 261906 is about 63.9806256459.

The spelling of 261906 in words is "two hundred sixty-one thousand, nine hundred six".