245665281 has 4 divisors (see below), whose sum is σ = 327553712. Its totient is φ = 163776852.

The previous prime is 245665271. The next prime is 245665289. The reversal of 245665281 is 182566542.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 245665281 - 2¹¹ = 245663233 is a prime.

It is a super-2 number, since 2×245665281² = 120702860577617922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (245665289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40944211 + ... + 40944216.

It is an arithmetic number, because the mean of its divisors is an integer number (81888428).

Almost surely, 2^245665281 is an apocalyptic number.

It is an amenable number.

245665281 is a deficient number, since it is larger than the sum of its proper divisors (81888431).

245665281 is an equidigital number, since it uses as much as digits as its factorization.

245665281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81888430.

The product of its digits is 115200, while the sum is 39.

The square root of 245665281 is about 15673.7130572178. The cubic root of 245665281 is about 626.2983408169.

The spelling of 245665281 in words is "two hundred forty-five million, six hundred sixty-five thousand, two hundred eighty-one".