212985709 has 4 divisors (see below), whose sum is σ = 216477340. Its totient is φ = 209494080.

The previous prime is 212985691. The next prime is 212985757. The reversal of 212985709 is 907589212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 24472809 + 188512900 = 4947^2 + 13730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212985709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212985109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1745724 + ... + 1745845.

It is an arithmetic number, because the mean of its divisors is an integer number (54119335).

Almost surely, 2^212985709 is an apocalyptic number.

It is an amenable number.

212985709 is a deficient number, since it is larger than the sum of its proper divisors (3491631).

212985709 is an equidigital number, since it uses as much as digits as its factorization.

212985709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3491630.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 212985709 is about 14594.0299095212. The cubic root of 212985709 is about 597.1959053184.

The spelling of 212985709 in words is "two hundred twelve million, nine hundred eighty-five thousand, seven hundred nine".