18749421 has 16 divisors (see below), whose sum is σ = 28067200. Its totient is φ = 12369024.

The previous prime is 18749377. The next prime is 18749429. The reversal of 18749421 is 12494781.

It is not a de Polignac number, because 18749421 - 2¹⁹ = 18225133 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18749429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 961 + ... + 6198.

It is an arithmetic number, because the mean of its divisors is an integer number (1754200).

Almost surely, 2^18749421 is an apocalyptic number.

It is an amenable number.

18749421 is a deficient number, since it is larger than the sum of its proper divisors (9317779).

18749421 is an equidigital number, since it uses as much as digits as its factorization.

18749421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7265 (or 7259 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 18749421 is about 4330.0601612449. The cubic root of 18749421 is about 265.6619076928.

The spelling of 18749421 in words is "eighteen million, seven hundred forty-nine thousand, four hundred twenty-one".