261854 has 4 divisors (see below), whose sum is σ = 392784. Its totient is φ = 130926.

The previous prime is 261847. The next prime is 261881. The reversal of 261854 is 458162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 458162 = 2 ⋅229081.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65462 + ... + 65465.

It is an arithmetic number, because the mean of its divisors is an integer number (98196).

261854 is a Friedman number, since it can be written as 8^6-145*2, using all its digits and the basic arithmetic operations.

2²⁶¹⁸⁵⁴ is an apocalyptic number.

261854 is a deficient number, since it is larger than the sum of its proper divisors (130930).

261854 is a wasteful number, since it uses less digits than its factorization.

261854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130929.

The product of its digits is 1920, while the sum is 26.

The square root of 261854 is about 511.7167185074. The cubic root of 261854 is about 63.9763910315.

The spelling of 261854 in words is "two hundred sixty-one thousand, eight hundred fifty-four".