18621109 has 8 divisors (see below), whose sum is σ = 20353760. Its totient is φ = 16931376.

The previous prime is 18621091. The next prime is 18621139. The reversal of 18621109 is 90112681.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18621109 - 2⁷ = 18620981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18621139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9819 + ... + 11560.

It is an arithmetic number, because the mean of its divisors is an integer number (2544220).

Almost surely, 2^18621109 is an apocalyptic number.

It is an amenable number.

18621109 is a deficient number, since it is larger than the sum of its proper divisors (1732651).

18621109 is a wasteful number, since it uses less digits than its factorization.

18621109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21459.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 18621109 is about 4315.2183027050. The cubic root of 18621109 is about 265.0544992930.

The spelling of 18621109 in words is "eighteen million, six hundred twenty-one thousand, one hundred nine".