820018918805 has 8 divisors (see below), whose sum is σ = 984162184152. Its totient is φ = 655922147328.

The previous prime is 820018918757. The next prime is 820018918861. The reversal of 820018918805 is 508819810028.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 137384387716 + 682634531089 = 370654^2 + 826217^2 .

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 820018918805 - 2²⁰ = 820017870229 is a prime.

It is a Duffinian number.

It is a congruent 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, 11584652 + ... + 11655221.

It is an arithmetic number, because the mean of its divisors is an integer number (123020273019).

Almost surely, 2^820018918805 is an apocalyptic number.

It is an amenable number.

820018918805 is a deficient number, since it is larger than the sum of its proper divisors (164143265347).

820018918805 is a wasteful number, since it uses less digits than its factorization.

820018918805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23246935.

The product of its (nonzero) digits is 368640, while the sum is 50.

The spelling of 820018918805 in words is "eight hundred twenty billion, eighteen million, nine hundred eighteen thousand, eight hundred five".