18934991 has 6 divisors (see below), whose sum is σ = 20114640. Its totient is φ = 17820896.

The previous prime is 18934987. The next prime is 18935011. The reversal of 18934991 is 19943981.

It is not a de Polignac number, because 18934991 - 2² = 18934987 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 (18930991) 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 5 ways as a sum of consecutive naturals, for example, 32471 + ... + 33048.

It is an arithmetic number, because the mean of its divisors is an integer number (3352440).

Almost surely, 2^18934991 is an apocalyptic number.

18934991 is a deficient number, since it is larger than the sum of its proper divisors (1179649).

18934991 is an equidigital number, since it uses as much as digits as its factorization.

18934991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65553 (or 65536 counting only the distinct ones).

The product of its digits is 69984, while the sum is 44.

The square root of 18934991 is about 4351.4355102655. The cubic root of 18934991 is about 266.5354835671.

The spelling of 18934991 in words is "eighteen million, nine hundred thirty-four thousand, nine hundred ninety-one".