820315785 has 32 divisors (see below), whose sum is σ = 1387728000. Its totient is φ = 412632576.

The previous prime is 820315751. The next prime is 820315801. The reversal of 820315785 is 587513028.

It is not a de Polignac number, because 820315785 - 2¹⁷ = 820184713 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 58981 + ... + 71549.

It is an arithmetic number, because the mean of its divisors is an integer number (43366500).

Almost surely, 2^820315785 is an apocalyptic number.

It is an amenable number.

820315785 is a deficient number, since it is larger than the sum of its proper divisors (567412215).

820315785 is a wasteful number, since it uses less digits than its factorization.

820315785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12825.

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

The square root of 820315785 is about 28641.1554410781. The cubic root of 820315785 is about 936.1102979725.

The spelling of 820315785 in words is "eight hundred twenty million, three hundred fifteen thousand, seven hundred eighty-five".