218313820 has 24 divisors (see below), whose sum is σ = 459232704. Its totient is φ = 87178176.

The previous prime is 218313793. The next prime is 218313829. The reversal of 218313820 is 28313812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218313829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3357 + ... + 21163.

It is an arithmetic number, because the mean of its divisors is an integer number (19134696).

Almost surely, 2^218313820 is an apocalyptic number.

218313820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218313820 is an abundant number, since it is smaller than the sum of its proper divisors (240918884).

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

218313820 is a wasteful number, since it uses less digits than its factorization.

218313820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18429 (or 18427 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 218313820 is about 14775.4465245555. The cubic root of 218313820 is about 602.1348211484.

It can be divided in two parts, 21831 and 3820, that added together give a triangular number (25651 = T₂₂₆).

The spelling of 218313820 in words is "two hundred eighteen million, three hundred thirteen thousand, eight hundred twenty".