18403918 has 16 divisors (see below), whose sum is σ = 29887200. Its totient is φ = 8449056.

The previous prime is 18403897. The next prime is 18403927. The reversal of 18403918 is 81930481.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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, 3396 + ... + 6952.

It is an arithmetic number, because the mean of its divisors is an integer number (1867950).

Almost surely, 2^18403918 is an apocalyptic number.

18403918 is a deficient number, since it is larger than the sum of its proper divisors (11483282).

18403918 is a wasteful number, since it uses less digits than its factorization.

18403918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3771.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 18403918 is about 4289.9787878263. The cubic root of 18403918 is about 264.0199613771.

It can be divided in two parts, 18403 and 918, that added together give a square (19321 = 139²).

The spelling of 18403918 in words is "eighteen million, four hundred three thousand, nine hundred eighteen".