191638212694 has 4 divisors (see below), whose sum is σ = 287457319044. Its totient is φ = 95819106346.

The previous prime is 191638212679. The next prime is 191638212721. The reversal of 191638212694 is 496212836191.

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

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 47909553172 + ... + 47909553175.

It is an arithmetic number, because the mean of its divisors is an integer number (71864329761).

Almost surely, 2^191638212694 is an apocalyptic number.

191638212694 is a deficient number, since it is larger than the sum of its proper divisors (95819106350).

191638212694 is an equidigital number, since it uses as much as digits as its factorization.

191638212694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95819106349.

The product of its digits is 1119744, while the sum is 52.

The spelling of 191638212694 in words is "one hundred ninety-one billion, six hundred thirty-eight million, two hundred twelve thousand, six hundred ninety-four".