261717256 has 8 divisors (see below), whose sum is σ = 490719870. Its totient is φ = 130858624.

The previous prime is 261717241. The next prime is 261717259. The reversal of 261717256 is 652717162.

It can be written as a sum of positive squares in only one way, i.e., 161036100 + 100681156 = 12690^2 + 10034^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (261717259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16357321 + ... + 16357336.

Almost surely, 2^261717256 is an apocalyptic number.

It is an amenable number.

261717256 is a deficient number, since it is larger than the sum of its proper divisors (229002614).

261717256 is a wasteful number, since it uses less digits than its factorization.

261717256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32714663 (or 32714659 counting only the distinct ones).

The product of its digits is 35280, while the sum is 37.

The square root of 261717256 is about 16177.6777072607. The cubic root of 261717256 is about 639.6525262247.

The spelling of 261717256 in words is "two hundred sixty-one million, seven hundred seventeen thousand, two hundred fifty-six".