18091983 has 16 divisors (see below), whose sum is σ = 29689856. Its totient is φ = 9542880.

The previous prime is 18091979. The next prime is 18091991. The reversal of 18091983 is 38919081.

It is a happy number.

It is not a de Polignac number, because 18091983 - 2² = 18091979 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18091963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32863 + ... + 33408.

It is an arithmetic number, because the mean of its divisors is an integer number (1855616).

Almost surely, 2^18091983 is an apocalyptic number.

18091983 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

18091983 is a deficient number, since it is larger than the sum of its proper divisors (11597873).

18091983 is a wasteful number, since it uses less digits than its factorization.

18091983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66294.

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 18091983 is about 4253.4671739653. The cubic root of 18091983 is about 262.5197953326.

The spelling of 18091983 in words is "eighteen million, ninety-one thousand, nine hundred eighty-three".