209212717087 has 16 divisors (see below), whose sum is σ = 229812129792. Its totient is φ = 188878770720.

The previous prime is 209212717057. The next prime is 209212717151. The reversal of 209212717087 is 780717212902.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209212717087 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 (209212717057) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1944433 + ... + 2049205.

It is an arithmetic number, because the mean of its divisors is an integer number (14363258112).

Almost surely, 2^209212717087 is an apocalyptic number.

209212717087 is a deficient number, since it is larger than the sum of its proper divisors (20599412705).

209212717087 is a wasteful number, since it uses less digits than its factorization.

209212717087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106038.

The product of its (nonzero) digits is 197568, while the sum is 46.

Adding to 209212717087 its reverse (780717212902), we get a palindrome (989929929989).

The spelling of 209212717087 in words is "two hundred nine billion, two hundred twelve million, seven hundred seventeen thousand, eighty-seven".