261438 has 8 divisors (see below), whose sum is σ = 522888. Its totient is φ = 87144.

The previous prime is 261433. The next prime is 261439. The reversal of 261438 is 834162.

It is a happy number.

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

261438 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21781 + ... + 21792.

It is an arithmetic number, because the mean of its divisors is an integer number (65361).

2²⁶¹⁴³⁸ is an apocalyptic number.

261438 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.

261438 is a wasteful number, since it uses less digits than its factorization.

261438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43578.

The product of its digits is 1152, while the sum is 24.

The square root of 261438 is about 511.3100820442. The cubic root of 261438 is about 63.9424939173.

The spelling of 261438 in words is "two hundred sixty-one thousand, four hundred thirty-eight".