210639009 has 16 divisors (see below), whose sum is σ = 322382720. Its totient is φ = 119836800.

The previous prime is 210639001. The next prime is 210639029. The reversal of 210639009 is 900936012.

It is not a de Polignac number, because 210639009 - 2³ = 210639001 is a prime.

It is a super-2 number, since 2×210639009² = 88737584225004162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210639001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17092 + ... + 26709.

It is an arithmetic number, because the mean of its divisors is an integer number (20148920).

Almost surely, 2^210639009 is an apocalyptic number.

It is an amenable number.

210639009 is a deficient number, since it is larger than the sum of its proper divisors (111743711).

210639009 is a wasteful number, since it uses less digits than its factorization.

210639009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44040.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 210639009 is about 14513.4079044172. The cubic root of 210639009 is about 594.9944767983.

The spelling of 210639009 in words is "two hundred ten million, six hundred thirty-nine thousand, nine".