218631920 has 120 divisors (see below), whose sum is σ = 559312416. Its totient is φ = 79432704.

The previous prime is 218631913. The next prime is 218631929. The reversal of 218631920 is 29136812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218631929) 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 23 ways as a sum of consecutive naturals, for example, 1392482 + ... + 1392638.

Almost surely, 2^218631920 is an apocalyptic number.

218631920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218631920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (279656208).

218631920 is an abundant number, since it is smaller than the sum of its proper divisors (340680496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218631920 is a wasteful number, since it uses less digits than its factorization.

218631920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299 (or 280 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 218631920 is about 14786.2070863356. The cubic root of 218631920 is about 602.4271314455.

It can be divided in two parts, 21 and 8631920, that multiplied together give a triangular number (181270320 = T₁₉₀₄₀).

The spelling of 218631920 in words is "two hundred eighteen million, six hundred thirty-one thousand, nine hundred twenty".