18991130 has 32 divisors (see below), whose sum is σ = 35140608. Its totient is φ = 7387200.

The previous prime is 18991129. The next prime is 18991139. The reversal of 18991130 is 3119981.

It is not an unprimeable number, because it can be changed into a prime (18991139) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99335 + ... + 99525.

It is an arithmetic number, because the mean of its divisors is an integer number (1098144).

Almost surely, 2^18991130 is an apocalyptic number.

18991130 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18991130 is a deficient number, since it is larger than the sum of its proper divisors (16149478).

18991130 is a wasteful number, since it uses less digits than its factorization.

18991130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422.

The product of its (nonzero) digits is 1944, while the sum is 32.

The square root of 18991130 is about 4357.8813659851. The cubic root of 18991130 is about 266.7986343340.

It can be divided in two parts, 189 and 91130, that added together give a palindrome (91319).

The spelling of 18991130 in words is "eighteen million, nine hundred ninety-one thousand, one hundred thirty".