191217940255 has 4 divisors (see below), whose sum is σ = 229461528312. Its totient is φ = 152974352200.

The previous prime is 191217940253. The next prime is 191217940267. The reversal of 191217940255 is 552049712191.

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

It is not a de Polignac number, because 191217940255 - 2¹ = 191217940253 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 (191217940253) 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, 19121794021 + ... + 19121794030.

It is an arithmetic number, because the mean of its divisors is an integer number (57365382078).

Almost surely, 2^191217940255 is an apocalyptic number.

191217940255 is a deficient number, since it is larger than the sum of its proper divisors (38243588057).

191217940255 is an equidigital number, since it uses as much as digits as its factorization.

191217940255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38243588056.

The product of its (nonzero) digits is 226800, while the sum is 46.

The spelling of 191217940255 in words is "one hundred ninety-one billion, two hundred seventeen million, nine hundred forty thousand, two hundred fifty-five".