191001000 has 64 divisors (see below), whose sum is σ = 595932480. Its totient is φ = 50932800.

The previous prime is 191000981. The next prime is 191001007. The reversal of 191001000 is 100191.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (191001007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28834 + ... + 34833.

It is an arithmetic number, because the mean of its divisors is an integer number (9311445).

Almost surely, 2^191001000 is an apocalyptic number.

191001000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191001000 is an abundant number, since it is smaller than the sum of its proper divisors (404931480).

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

191001000 is a wasteful number, since it uses less digits than its factorization.

191001000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63691 (or 63677 counting only the distinct ones).

The product of its (nonzero) digits is 9, while the sum is 12.

The square root of 191001000 is about 13820.3111397682. The cubic root of 191001000 is about 575.8975271025.

Adding to 191001000 its reverse (100191), we get a palindrome (191101191).

It can be divided in two parts, 19100 and 1000, that added together give a triangular number (20100 = T₂₀₀).

The spelling of 191001000 in words is "one hundred ninety-one million, one thousand".