820385617 has 8 divisors (see below), whose sum is σ = 834140160. Its totient is φ = 806692320.

The previous prime is 820385603. The next prime is 820385623. The reversal of 820385617 is 716583028.

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 820385617 - 2²³ = 811997009 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 820385617.

It is not an unprimeable number, because it can be changed into a prime (820385647) 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, 12109 + ... + 42277.

It is an arithmetic number, because the mean of its divisors is an integer number (104267520).

Almost surely, 2^820385617 is an apocalyptic number.

It is an amenable number.

820385617 is a deficient number, since it is larger than the sum of its proper divisors (13754543).

820385617 is a wasteful number, since it uses less digits than its factorization.

820385617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30623.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 820385617 is about 28642.3745000305. The cubic root of 820385617 is about 936.1368603446.

The spelling of 820385617 in words is "eight hundred twenty million, three hundred eighty-five thousand, six hundred seventeen".