820578716164 has 15 divisors (see below), whose sum is σ = 1438149677027. Its totient is φ = 409679715648.

The previous prime is 820578716141. The next prime is 820578716173. The reversal of 820578716164 is 461617875028.

The square root of 820578716164 is 905858.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 97942709764 + 722636006400 = 312958^2 + 850080^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=4, B=673.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 4 ways as a sum of consecutive naturals, for example, 1219284532 + ... + 1219285204.

Almost surely, 2^820578716164 is an apocalyptic number.

820578716164 is the 905858-th square number.

It is an amenable number.

820578716164 is a deficient number, since it is larger than the sum of its proper divisors (617570960863).

820578716164 is an frugal number, since it uses more digits than its factorization.

820578716164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2696 (or 675 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 55.

The spelling of 820578716164 in words is "eight hundred twenty billion, five hundred seventy-eight million, seven hundred sixteen thousand, one hundred sixty-four".