245661287 has 4 divisors (see below), whose sum is σ = 247536696. Its totient is φ = 243785880.

The previous prime is 245661253. The next prime is 245661289. The reversal of 245661287 is 782166542.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 782166542 = 2 ⋅391083271.

It is a cyclic number.

It is not a de Polignac number, because 245661287 - 2⁶ = 245661223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (245661289) 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 3 ways as a sum of consecutive naturals, for example, 937508 + ... + 937769.

It is an arithmetic number, because the mean of its divisors is an integer number (61884174).

Almost surely, 2^245661287 is an apocalyptic number.

245661287 is a deficient number, since it is larger than the sum of its proper divisors (1875409).

245661287 is a wasteful number, since it uses less digits than its factorization.

245661287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1875408.

The product of its digits is 161280, while the sum is 41.

The square root of 245661287 is about 15673.5856459203. The cubic root of 245661287 is about 626.2949467012.

The spelling of 245661287 in words is "two hundred forty-five million, six hundred sixty-one thousand, two hundred eighty-seven".