820018 has 4 divisors (see below), whose sum is σ = 1230030. Its totient is φ = 410008.

The previous prime is 819991. The next prime is 820037. The reversal of 820018 is 810028.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 567009 + 253009 = 753^2 + 503^2 .

It is a plaindrome in base 12.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 819977 and 820004.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205003 + ... + 205006.

2⁸²⁰⁰¹⁸ is an apocalyptic number.

820018 is a deficient number, since it is larger than the sum of its proper divisors (410012).

820018 is a wasteful number, since it uses less digits than its factorization.

820018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410011.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 820018 is about 905.5484525965. The cubic root of 820018 is about 93.5997010973.

The spelling of 820018 in words is "eight hundred twenty thousand, eighteen".