191028090 has 64 divisors (see below), whose sum is σ = 526487040. Its totient is φ = 43871040.

The previous prime is 191028073. The next prime is 191028091. The reversal of 191028090 is 90820191.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (191028091) by changing a digit.

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 in 31 ways as a sum of consecutive naturals, for example, 8964 + ... + 21503.

It is an arithmetic number, because the mean of its divisors is an integer number (8226360).

Almost surely, 2^191028090 is an apocalyptic number.

191028090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

191028090 is an abundant number, since it is smaller than the sum of its proper divisors (335458950).

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

191028090 is a wasteful number, since it uses less digits than its factorization.

191028090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30507.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 191028090 is about 13821.2911842563. The cubic root of 191028090 is about 575.9247526606.

The spelling of 191028090 in words is "one hundred ninety-one million, twenty-eight thousand, ninety".