261501241 has 9 divisors (see below), whose sum is σ = 265757391. Its totient is φ = 257312952.

The previous prime is 261501223. The next prime is 261501269. The reversal of 261501241 is 142105162.

The square root of 261501241 is 16171.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 76650025 + 184851216 = 8755^2 + 13596^2 .

It is not a de Polignac number, because 261501241 - 2⁵ = 261501209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261501271) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1665535 + ... + 1665691.

It is an arithmetic number, because the mean of its divisors is an integer number (29528599).

Almost surely, 2^261501241 is an apocalyptic number.

261501241 is the 16171-st square number.

261501241 is the 8086-th centered octagonal number.

It is an amenable number.

261501241 is a deficient number, since it is larger than the sum of its proper divisors (4256150).

261501241 is an frugal number, since it uses more digits than its factorization.

261501241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520 (or 260 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The cubic root of 261501241 is about 639.4764932859.

The spelling of 261501241 in words is "two hundred sixty-one million, five hundred one thousand, two hundred forty-one".