218585421 has 24 divisors (see below), whose sum is σ = 319629024. Its totient is φ = 143938080.

The previous prime is 218585413. The next prime is 218585459. The reversal of 218585421 is 124585812.

218585421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 218585421 - 2³ = 218585413 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218585401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 467830 + ... + 468296.

It is an arithmetic number, because the mean of its divisors is an integer number (13317876).

Almost surely, 2^218585421 is an apocalyptic number.

It is an amenable number.

218585421 is a deficient number, since it is larger than the sum of its proper divisors (101043603).

218585421 is a wasteful number, since it uses less digits than its factorization.

218585421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001 (or 998 counting only the distinct ones).

The product of its digits is 25600, while the sum is 36.

The square root of 218585421 is about 14784.6346251776. The cubic root of 218585421 is about 602.3844200163.

The spelling of 218585421 in words is "two hundred eighteen million, five hundred eighty-five thousand, four hundred twenty-one".