209512071 has 12 divisors (see below), whose sum is σ = 302810248. Its totient is φ = 139590864.

The previous prime is 209512067. The next prime is 209512073. The reversal of 209512071 is 170215902.

It is not a de Polignac number, because 209512071 - 2² = 209512067 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 (209512073) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11376 + ... + 23418.

Almost surely, 2^209512071 is an apocalyptic number.

209512071 is a deficient number, since it is larger than the sum of its proper divisors (93298177).

209512071 is a wasteful number, since it uses less digits than its factorization.

209512071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13982 (or 13979 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 209512071 is about 14474.5318058996. The cubic root of 209512071 is about 593.9314871835.

Adding to 209512071 its reverse (170215902), we get a palindrome (379727973).

The spelling of 209512071 in words is "two hundred nine million, five hundred twelve thousand, seventy-one".