261055257 has 8 divisors (see below), whose sum is σ = 348236160. Its totient is φ = 173955600.

The previous prime is 261055237. The next prime is 261055259. The reversal of 261055257 is 752550162.

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

It is not a de Polignac number, because 261055257 - 2¹⁴ = 261038873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261055259) 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, 12369 + ... + 25982.

It is an arithmetic number, because the mean of its divisors is an integer number (43529520).

Almost surely, 2^261055257 is an apocalyptic number.

It is an amenable number.

261055257 is a deficient number, since it is larger than the sum of its proper divisors (87180903).

261055257 is a wasteful number, since it uses less digits than its factorization.

261055257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40623.

The product of its (nonzero) digits is 21000, while the sum is 33.

The square root of 261055257 is about 16157.2044921143. The cubic root of 261055257 is about 639.1127492250.

The spelling of 261055257 in words is "two hundred sixty-one million, fifty-five thousand, two hundred fifty-seven".