820500660 has 72 divisors (see below), whose sum is σ = 2844406656. Its totient is φ = 187542720.

The previous prime is 820500619. The next prime is 820500671. The reversal of 820500660 is 66005028.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 324336 + ... + 326855.

It is an arithmetic number, because the mean of its divisors is an integer number (39505648).

Almost surely, 2^820500660 is an apocalyptic number.

It is an amenable number.

820500660 is an abundant number, since it is smaller than the sum of its proper divisors (2023905996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820500660 is a wasteful number, since it uses less digits than its factorization.

820500660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651213 (or 651208 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 820500660 is about 28644.3826953907. The cubic root of 820500660 is about 936.1806165803.

Adding to 820500660 its reverse (66005028), we get a palindrome (886505688).

The spelling of 820500660 in words is "eight hundred twenty million, five hundred thousand, six hundred sixty".