18909508 has 48 divisors (see below), whose sum is σ = 37255680. Its totient is φ = 8354304.

The previous prime is 18909497. The next prime is 18909509. The reversal of 18909508 is 80590981.

It is not an unprimeable number, because it can be changed into a prime (18909509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84685 + ... + 84907.

It is an arithmetic number, because the mean of its divisors is an integer number (776160).

Almost surely, 2^18909508 is an apocalyptic number.

It is an amenable number.

18909508 is a deficient number, since it is larger than the sum of its proper divisors (18346172).

18909508 is a wasteful number, since it uses less digits than its factorization.

18909508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316 (or 314 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 40.

The square root of 18909508 is about 4348.5064102517. The cubic root of 18909508 is about 266.4158607131.

The spelling of 18909508 in words is "eighteen million, nine hundred nine thousand, five hundred eight".