18217938 has 16 divisors (see below), whose sum is σ = 36648576. Its totient is φ = 6037200.

The previous prime is 18217937. The next prime is 18217957. The reversal of 18217938 is 83971281.

It is a junction number, because it is equal to n+sod(n) for n = 18217896 and 18217905.

It is not an unprimeable number, because it can be changed into a prime (18217937) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7738 + ... + 9813.

It is an arithmetic number, because the mean of its divisors is an integer number (2290536).

Almost surely, 2^18217938 is an apocalyptic number.

18217938 is an abundant number, since it is smaller than the sum of its proper divisors (18430638).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18217938 is a wasteful number, since it uses less digits than its factorization.

18217938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17729.

The product of its digits is 24192, while the sum is 39.

The square root of 18217938 is about 4268.2476497973. The cubic root of 18217938 is about 263.1276012441.

The spelling of 18217938 in words is "eighteen million, two hundred seventeen thousand, nine hundred thirty-eight".