261929 has 4 divisors (see below), whose sum is σ = 264576. Its totient is φ = 259284.

The previous prime is 261917. The next prime is 261959. The reversal of 261929 is 929162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261929 - 2⁸ = 261673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261959) 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 3 ways as a sum of consecutive naturals, for example, 1169 + ... + 1374.

It is an arithmetic number, because the mean of its divisors is an integer number (66144).

2²⁶¹⁹²⁹ is an apocalyptic number.

It is an amenable number.

261929 is a deficient number, since it is larger than the sum of its proper divisors (2647).

261929 is a wasteful number, since it uses less digits than its factorization.

261929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2646.

The product of its digits is 1944, while the sum is 29.

The square root of 261929 is about 511.7899959945. The cubic root of 261929 is about 63.9824984697.

The spelling of 261929 in words is "two hundred sixty-one thousand, nine hundred twenty-nine".