191991006 has 32 divisors (see below), whose sum is σ = 427806720. Its totient is φ = 63823032.

The previous prime is 191990999. The next prime is 191991043. The reversal of 191991006 is 600199191.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16041 + ... + 25323.

It is an arithmetic number, because the mean of its divisors is an integer number (13368960).

Almost surely, 2^191991006 is an apocalyptic number.

191991006 is an abundant number, since it is smaller than the sum of its proper divisors (235815714).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191991006 is a wasteful number, since it uses less digits than its factorization.

191991006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9677 (or 9671 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 36.

The square root of 191991006 is about 13856.0819137302. The cubic root of 191991006 is about 576.8908199319.

The spelling of 191991006 in words is "one hundred ninety-one million, nine hundred ninety-one thousand, six".