18948909 has 16 divisors (see below), whose sum is σ = 30394880. Its totient is φ = 10257840.

The previous prime is 18948907. The next prime is 18948949. The reversal of 18948909 is 90984981.

It is not a de Polignac number, because 18948909 - 2¹ = 18948907 is a prime.

It is a super-2 number, since 2×18948909² = 718122304580562, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18948907) 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, 23347 + ... + 24144.

It is an arithmetic number, because the mean of its divisors is an integer number (1899680).

Almost surely, 2^18948909 is an apocalyptic number.

18948909 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18948909 is a deficient number, since it is larger than the sum of its proper divisors (11445971).

18948909 is a wasteful number, since it uses less digits than its factorization.

18948909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47520.

The product of its (nonzero) digits is 186624, while the sum is 48.

The square root of 18948909 is about 4353.0344588574. The cubic root of 18948909 is about 266.6007724339.

The spelling of 18948909 in words is "eighteen million, nine hundred forty-eight thousand, nine hundred nine".