261957289 has 8 divisors (see below), whose sum is σ = 287859168. Its totient is φ = 236403360.

The previous prime is 261957271. The next prime is 261957317. The reversal of 261957289 is 982759162.

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 261957289 - 2¹¹ = 261955241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261957239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85407 + ... + 88420.

It is an arithmetic number, because the mean of its divisors is an integer number (35982396).

Almost surely, 2^261957289 is an apocalyptic number.

It is an amenable number.

261957289 is a deficient number, since it is larger than the sum of its proper divisors (25901879).

261957289 is a wasteful number, since it uses less digits than its factorization.

261957289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173975.

The product of its digits is 544320, while the sum is 49.

The square root of 261957289 is about 16185.0946552685. The cubic root of 261957289 is about 639.8480181107.

The spelling of 261957289 in words is "two hundred sixty-one million, nine hundred fifty-seven thousand, two hundred eighty-nine".