820666028 has 36 divisors (see below), whose sum is σ = 1777310640. Its totient is φ = 324657216.

The previous prime is 820666019. The next prime is 820666057.

820666028 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 820665982 and 820666000.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 81983 + ... + 91446.

It is an arithmetic number, because the mean of its divisors is an integer number (49369740).

Almost surely, 2^820666028 is an apocalyptic number.

It is an amenable number.

820666028 is an abundant number, since it is smaller than the sum of its proper divisors (956644612).

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

820666028 is a wasteful number, since it uses less digits than its factorization.

820666028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173466 (or 173451 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 820666028 is about 28647.2691194117. The cubic root of 820666028 is about 936.2435066035.

The spelling of 820666028 in words is "eight hundred twenty million, six hundred sixty-six thousand, twenty-eight".