209780164257 has 16 divisors (see below), whose sum is σ = 280507432128. Its totient is φ = 139453306560.

The previous prime is 209780164249. The next prime is 209780164277. The reversal of 209780164257 is 752461087902.

It is a happy number.

It is not a de Polignac number, because 209780164257 - 2³ = 209780164249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209780164207) 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, 7787103 + ... + 7813995.

It is an arithmetic number, because the mean of its divisors is an integer number (17531714508).

Almost surely, 2^209780164257 is an apocalyptic number.

It is an amenable number.

209780164257 is a deficient number, since it is larger than the sum of its proper divisors (70727267871).

209780164257 is a wasteful number, since it uses less digits than its factorization.

209780164257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34240.

The product of its (nonzero) digits is 1693440, while the sum is 51.

The spelling of 209780164257 in words is "two hundred nine billion, seven hundred eighty million, one hundred sixty-four thousand, two hundred fifty-seven".