261746245 has 8 divisors (see below), whose sum is σ = 318398616. Its totient is φ = 206528256.

The previous prime is 261746207. The next prime is 261746249. The reversal of 261746245 is 542647162.

It can be written as a sum of positive squares in 4 ways, for example, as 17355556 + 244390689 = 4166^2 + 15633^2 .

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 261746245 - 2¹⁷ = 261615173 is a prime.

It is a super-2 number, since 2×261746245² = 137022193543200050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261746249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 358192 + ... + 358921.

It is an arithmetic number, because the mean of its divisors is an integer number (39799827).

Almost surely, 2^261746245 is an apocalyptic number.

It is an amenable number.

261746245 is a deficient number, since it is larger than the sum of its proper divisors (56652371).

261746245 is an equidigital number, since it uses as much as digits as its factorization.

261746245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717191.

The product of its digits is 80640, while the sum is 37.

The square root of 261746245 is about 16178.5736392304. The cubic root of 261746245 is about 639.6761422990.

The spelling of 261746245 in words is "two hundred sixty-one million, seven hundred forty-six thousand, two hundred forty-five".