261340 has 24 divisors (see below), whose sum is σ = 559440. Its totient is φ = 102528.

The previous prime is 261337. The next prime is 261347. The reversal of 261340 is 43162.

261340 = 20² + 21² + ... + 92².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261347) 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 7 ways as a sum of consecutive naturals, for example, 1371 + ... + 1549.

It is an arithmetic number, because the mean of its divisors is an integer number (23310).

2²⁶¹³⁴⁰ is an apocalyptic number.

261340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261340 is an abundant number, since it is smaller than the sum of its proper divisors (298100).

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

261340 is a wasteful number, since it uses less digits than its factorization.

261340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 261340 is about 511.2142408032. The cubic root of 261340 is about 63.9345033070.

The spelling of 261340 in words is "two hundred sixty-one thousand, three hundred forty".