191009191900 has 18 divisors (see below), whose sum is σ = 414489946640. Its totient is φ = 76403676720.

The previous prime is 191009191871. The next prime is 191009191909. The reversal of 191009191900 is 9191900191.

It is a super-2 number, since 2×191009191900² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191009191909) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 955045860 + ... + 955046059.

Almost surely, 2^191009191900 is an apocalyptic number.

191009191900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191009191900 is an abundant number, since it is smaller than the sum of its proper divisors (223480754740).

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

191009191900 is a wasteful number, since it uses less digits than its factorization.

191009191900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1910091933 (or 1910091926 counting only the distinct ones).

The product of its (nonzero) digits is 6561, while the sum is 40.

The spelling of 191009191900 in words is "one hundred ninety-one billion, nine million, one hundred ninety-one thousand, nine hundred".