18409923 has 48 divisors (see below), whose sum is σ = 32148480. Its totient is φ = 10310976.

The previous prime is 18409907. The next prime is 18409933. The reversal of 18409923 is 32990481.

It is not a de Polignac number, because 18409923 - 2⁴ = 18409907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18409933) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 134311 + ... + 134447.

It is an arithmetic number, because the mean of its divisors is an integer number (669760).

Almost surely, 2^18409923 is an apocalyptic number.

18409923 is a deficient number, since it is larger than the sum of its proper divisors (13738557).

18409923 is an equidigital number, since it uses as much as digits as its factorization.

18409923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238 (or 226 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 18409923 is about 4290.6786176548. The cubic root of 18409923 is about 264.0486738766.

The spelling of 18409923 in words is "eighteen million, four hundred nine thousand, nine hundred twenty-three".