218484021 has 32 divisors (see below), whose sum is σ = 356428800. Its totient is φ = 116259840.

The previous prime is 218484011. The next prime is 218484023. The reversal of 218484021 is 120484812.

218484021 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 218484021 - 2⁷ = 218483893 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 218484021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218484023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18901 + ... + 28181.

It is an arithmetic number, because the mean of its divisors is an integer number (11138400).

Almost surely, 2^218484021 is an apocalyptic number.

218484021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

218484021 is a deficient number, since it is larger than the sum of its proper divisors (137944779).

218484021 is a wasteful number, since it uses less digits than its factorization.

218484021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9369.

The product of its (nonzero) digits is 4096, while the sum is 30.

The square root of 218484021 is about 14781.2049914748. The cubic root of 218484021 is about 602.2912585306.

The spelling of 218484021 in words is "two hundred eighteen million, four hundred eighty-four thousand, twenty-one".