210820009 has 12 divisors (see below), whose sum is σ = 225480448. Its totient is φ = 197064000.

The previous prime is 210819997. The next prime is 210820019. The reversal of 210820009 is 900028012.

210820009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 210820009 - 2⁵ = 210819977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (210820019) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41224 + ... + 46054.

Almost surely, 2^210820009 is an apocalyptic number.

It is an amenable number.

210820009 is a deficient number, since it is larger than the sum of its proper divisors (14660439).

210820009 is a wasteful number, since it uses less digits than its factorization.

210820009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5016 (or 4999 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 210820009 is about 14519.6421787866. The cubic root of 210820009 is about 595.1648522806.

The spelling of 210820009 in words is "two hundred ten million, eight hundred twenty thousand, nine".