209218696971 has 4 divisors (see below), whose sum is σ = 278958262632. Its totient is φ = 139479131312.

The previous prime is 209218696937. The next prime is 209218696987. The reversal of 209218696971 is 179696812902.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209218696971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209218691971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34869782826 + ... + 34869782831.

It is an arithmetic number, because the mean of its divisors is an integer number (69739565658).

Almost surely, 2^209218696971 is an apocalyptic number.

209218696971 is a deficient number, since it is larger than the sum of its proper divisors (69739565661).

209218696971 is an equidigital number, since it uses as much as digits as its factorization.

209218696971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69739565660.

The product of its (nonzero) digits is 5878656, while the sum is 60.

The spelling of 209218696971 in words is "two hundred nine billion, two hundred eighteen million, six hundred ninety-six thousand, nine hundred seventy-one".