213500009 has 2 divisors, whose sum is σ = 213500010. Its totient is φ = 213500008.

The previous prime is 213500003. The next prime is 213500041. The reversal of 213500009 is 900005312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 112296409 + 101203600 = 10597^2 + 10060^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213500009 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (213500003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106750004 + 106750005.

It is an arithmetic number, because the mean of its divisors is an integer number (106750005).

Almost surely, 2^213500009 is an apocalyptic number.

It is an amenable number.

213500009 is a deficient number, since it is larger than the sum of its proper divisors (1).

213500009 is an equidigital number, since it uses as much as digits as its factorization.

213500009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 213500009 is about 14611.6395041761. The cubic root of 213500009 is about 597.6762050996.

The spelling of 213500009 in words is "two hundred thirteen million, five hundred thousand, nine".