261574 has 4 divisors (see below), whose sum is σ = 392364. Its totient is φ = 130786.

The previous prime is 261563. The next prime is 261577. The reversal of 261574 is 475162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 475162 = 2 ⋅237581.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261577) 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 as a sum of consecutive naturals, namely, 65392 + ... + 65395.

It is an arithmetic number, because the mean of its divisors is an integer number (98091).

2²⁶¹⁵⁷⁴ is an apocalyptic number.

261574 is a deficient number, since it is larger than the sum of its proper divisors (130790).

261574 is a wasteful number, since it uses less digits than its factorization.

261574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130789.

The product of its digits is 1680, while the sum is 25.

The square root of 261574 is about 511.4430564589. The cubic root of 261574 is about 63.9535796198.

It can be divided in two parts, 26 and 1574, that added together give a square (1600 = 40²).

The spelling of 261574 in words is "two hundred sixty-one thousand, five hundred seventy-four".