210820730 has 16 divisors (see below), whose sum is σ = 381110184. Its totient is φ = 83965440.

The previous prime is 210820721. The next prime is 210820733. The reversal of 210820730 is 37028012.

It can be written as a sum of positive squares in 4 ways, for example, as 87366409 + 123454321 = 9347^2 + 11111^2 .

It is a junction number, because it is equal to n+sod(n) for n = 210820696 and 210820705.

It is not an unprimeable number, because it can be changed into a prime (210820733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42911 + ... + 47570.

Almost surely, 2^210820730 is an apocalyptic number.

210820730 is a deficient number, since it is larger than the sum of its proper divisors (170289454).

210820730 is a wasteful number, since it uses less digits than its factorization.

210820730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90721.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 210820730 is about 14519.6670072010. The cubic root of 210820730 is about 595.1655307635.

Adding to 210820730 its reverse (37028012), we get a palindrome (247848742).

The spelling of 210820730 in words is "two hundred ten million, eight hundred twenty thousand, seven hundred thirty".