845217561 has 8 divisors (see below), whose sum is σ = 1133705664. Its totient is φ = 560103920.

The previous prime is 845217523. The next prime is 845217563. The reversal of 845217561 is 165712548.

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 845217561 - 2⁹ = 845217049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (845217563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 843030 + ... + 844031.

It is an arithmetic number, because the mean of its divisors is an integer number (141713208).

Almost surely, 2^845217561 is an apocalyptic number.

It is an amenable number.

845217561 is a deficient number, since it is larger than the sum of its proper divisors (288488103).

845217561 is a wasteful number, since it uses less digits than its factorization.

845217561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1687231.

The product of its digits is 67200, while the sum is 39.

The square root of 845217561 is about 29072.6256296194. The cubic root of 845217561 is about 945.4883252037.

The spelling of 845217561 in words is "eight hundred forty-five million, two hundred seventeen thousand, five hundred sixty-one".