261709231 has 8 divisors (see below), whose sum is σ = 299500544. Its totient is φ = 224019000.

The previous prime is 261709229. The next prime is 261709247. The reversal of 261709231 is 132907162.

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

It is a cyclic number.

It is not a de Polignac number, because 261709231 - 2¹ = 261709229 is a prime.

It is a super-2 number, since 2×261709231² = 136983443181222722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261709193 and 261709202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261709031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19635 + ... + 30148.

It is an arithmetic number, because the mean of its divisors is an integer number (37437568).

Almost surely, 2^261709231 is an apocalyptic number.

261709231 is a deficient number, since it is larger than the sum of its proper divisors (37791313).

261709231 is an equidigital number, since it uses as much as digits as its factorization.

261709231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50541.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 261709231 is about 16177.4296784131. The cubic root of 261709231 is about 639.6459882989.

The spelling of 261709231 in words is "two hundred sixty-one million, seven hundred nine thousand, two hundred thirty-one".