209497678397 has 8 divisors (see below), whose sum is σ = 240748714752. Its totient is φ = 178577341200.

The previous prime is 209497678391. The next prime is 209497678409. The reversal of 209497678397 is 793876794902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 209497678397 - 2⁸ = 209497678141 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 209497678397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209497678391) 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 7 ways as a sum of consecutive naturals, for example, 82673429 + ... + 82675962.

It is an arithmetic number, because the mean of its divisors is an integer number (30093589344).

Almost surely, 2^209497678397 is an apocalyptic number.

It is an amenable number.

209497678397 is a deficient number, since it is larger than the sum of its proper divisors (31251036355).

209497678397 is a wasteful number, since it uses less digits than its factorization.

209497678397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165349579.

The product of its (nonzero) digits is 288054144, while the sum is 71.

The spelling of 209497678397 in words is "two hundred nine billion, four hundred ninety-seven million, six hundred seventy-eight thousand, three hundred ninety-seven".