820213685 has 8 divisors (see below), whose sum is σ = 1005198336. Its totient is φ = 642209680.

The previous prime is 820213661. The next prime is 820213711. The reversal of 820213685 is 586312028.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-820213685 is a prime.

It is a super-2 number, since 2×820213685² = 1345500978122558450, which contains 22 as substring.

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, 1744901 + ... + 1745370.

It is an arithmetic number, because the mean of its divisors is an integer number (125649792).

Almost surely, 2^820213685 is an apocalyptic number.

It is an amenable number.

820213685 is a deficient number, since it is larger than the sum of its proper divisors (184984651).

820213685 is a wasteful number, since it uses less digits than its factorization.

820213685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3490323.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 820213685 is about 28639.3729854548. The cubic root of 820213685 is about 936.0714589348.

The spelling of 820213685 in words is "eight hundred twenty million, two hundred thirteen thousand, six hundred eighty-five".