18421191 has 6 divisors (see below), whose sum is σ = 26608400. Its totient is φ = 12280788.

The previous prime is 18421129. The next prime is 18421201. The reversal of 18421191 is 19112481.

It is not a de Polignac number, because 18421191 - 2⁹ = 18420679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18421111) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1023391 + ... + 1023408.

Almost surely, 2^18421191 is an apocalyptic number.

18421191 is a deficient number, since it is larger than the sum of its proper divisors (8187209).

18421191 is a wasteful number, since it uses less digits than its factorization.

18421191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2046805 (or 2046802 counting only the distinct ones).

The product of its digits is 576, while the sum is 27.

The square root of 18421191 is about 4291.9914957977. The cubic root of 18421191 is about 264.1025342077.

The spelling of 18421191 in words is "eighteen million, four hundred twenty-one thousand, one hundred ninety-one".