18938009421 has 12 divisors (see below), whose sum is σ = 27411079072. Its totient is φ = 12599411976.

The previous prime is 18938009413. The next prime is 18938009443. The reversal of 18938009421 is 12490083981.

18938009421 is a `hidden beast` number, since 189 + 380 + 0 + 94 + 2 + 1 = 666.

It is not a de Polignac number, because 18938009421 - 2³ = 18938009413 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 (18938009021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2156011 + ... + 2164776.

Almost surely, 2^18938009421 is an apocalyptic number.

It is an amenable number.

18938009421 is a deficient number, since it is larger than the sum of its proper divisors (8473069651).

18938009421 is a wasteful number, since it uses less digits than its factorization.

18938009421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4321280 (or 4321277 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 18938009421 in words is "eighteen billion, nine hundred thirty-eight million, nine thousand, four hundred twenty-one".