218121454 has 16 divisors (see below), whose sum is σ = 334582848. Its totient is φ = 106600032.

The previous prime is 218121451. The next prime is 218121469. The reversal of 218121454 is 454121812.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218121451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135784 + ... + 137380.

It is an arithmetic number, because the mean of its divisors is an integer number (20911428).

Almost surely, 2^218121454 is an apocalyptic number.

218121454 is a deficient number, since it is larger than the sum of its proper divisors (116461394).

218121454 is a wasteful number, since it uses less digits than its factorization.

218121454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3099.

The product of its digits is 2560, while the sum is 28.

The square root of 218121454 is about 14768.9354389543. The cubic root of 218121454 is about 601.9579132691.

The spelling of 218121454 in words is "two hundred eighteen million, one hundred twenty-one thousand, four hundred fifty-four".