18941391 has 48 divisors (see below), whose sum is σ = 33196800. Its totient is φ = 10641456.

The previous prime is 18941387. The next prime is 18941393. The reversal of 18941391 is 19314981.

It is not a de Polignac number, because 18941391 - 2² = 18941387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18941393) 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 47 ways as a sum of consecutive naturals, for example, 136200 + ... + 136338.

It is an arithmetic number, because the mean of its divisors is an integer number (691600).

Almost surely, 2^18941391 is an apocalyptic number.

18941391 is a deficient number, since it is larger than the sum of its proper divisors (14255409).

18941391 is a wasteful number, since it uses less digits than its factorization.

18941391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265 (or 252 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 18941391 is about 4352.1708376395. The cubic root of 18941391 is about 266.5655097224.

The spelling of 18941391 in words is "eighteen million, nine hundred forty-one thousand, three hundred ninety-one".