18491943 has 16 divisors (see below), whose sum is σ = 25452000. Its totient is φ = 11934720.

The previous prime is 18491939. The next prime is 18491951. The reversal of 18491943 is 34919481.

It is not a de Polignac number, because 18491943 - 2² = 18491939 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18491243) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 17823 + ... + 18831.

It is an arithmetic number, because the mean of its divisors is an integer number (1590750).

Almost surely, 2^18491943 is an apocalyptic number.

18491943 is a deficient number, since it is larger than the sum of its proper divisors (6960057).

18491943 is a wasteful number, since it uses less digits than its factorization.

18491943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1202.

The product of its digits is 31104, while the sum is 39.

The square root of 18491943 is about 4300.2259242975. The cubic root of 18491943 is about 264.4402233880.

The spelling of 18491943 in words is "eighteen million, four hundred ninety-one thousand, nine hundred forty-three".