18018218421 has 72 divisors (see below), whose sum is σ = 30999937280. Its totient is φ = 10258464672.

The previous prime is 18018218401. The next prime is 18018218429. The reversal of 18018218421 is 12481281081.

18018218421 is a `hidden beast` number, since 1 + 8 + 0 + 18 + 218 + 421 = 666.

It is not a de Polignac number, because 18018218421 - 2⁷ = 18018218293 is a prime.

It is a super-3 number, since 3×18018218421³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18018218429) 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 71 ways as a sum of consecutive naturals, for example, 16854675 + ... + 16855743.

Almost surely, 2^18018218421 is an apocalyptic number.

It is an amenable number.

18018218421 is a deficient number, since it is larger than the sum of its proper divisors (12981718859).

18018218421 is an frugal number, since it uses more digits than its factorization.

18018218421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1467 (or 1446 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 36.

The spelling of 18018218421 in words is "eighteen billion, eighteen million, two hundred eighteen thousand, four hundred twenty-one".