8217856945 has 8 divisors (see below), whose sum is σ = 9939078144. Its totient is φ = 6522519024.

The previous prime is 8217856937. The next prime is 8217856981. The reversal of 8217856945 is 5496587128.

It is a happy number.

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 8217856945 - 2³ = 8217856937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6470119 + ... + 6471388.

It is an arithmetic number, because the mean of its divisors is an integer number (1242384768).

Almost surely, 2^8217856945 is an apocalyptic number.

It is an amenable number.

8217856945 is a deficient number, since it is larger than the sum of its proper divisors (1721221199).

8217856945 is a wasteful number, since it uses less digits than its factorization.

8217856945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12941639.

The product of its digits is 4838400, while the sum is 55.

The square root of 8217856945 is about 90652.3962452179. The cubic root of 8217856945 is about 2017.9923968599.

The spelling of 8217856945 in words is "eight billion, two hundred seventeen million, eight hundred fifty-six thousand, nine hundred forty-five".