261968 has 20 divisors (see below), whose sum is σ = 580320. Its totient is φ = 112224.

The previous prime is 261959. The next prime is 261971. The reversal of 261968 is 869162.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a nialpdrome in base 4 and base 8.

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

261968 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1058 + ... + 1281.

It is an arithmetic number, because the mean of its divisors is an integer number (29016).

261968 is a Friedman number, since it can be written as 8^6-16*(9+2), using all its digits and the basic arithmetic operations.

2²⁶¹⁹⁶⁸ is an apocalyptic number.

261968 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

261968 is an abundant number, since it is smaller than the sum of its proper divisors (318352).

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

261968 is a wasteful number, since it uses less digits than its factorization.

261968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2354 (or 2348 counting only the distinct ones).

The product of its digits is 5184, while the sum is 32.

The square root of 261968 is about 511.8280961417. The cubic root of 261968 is about 63.9856738767.

The spelling of 261968 in words is "two hundred sixty-one thousand, nine hundred sixty-eight".