218971900 has 72 divisors (see below), whose sum is σ = 575025696. Its totient is φ = 70656000.

The previous prime is 218971897. The next prime is 218971913. The reversal of 218971900 is 9179812.

It is a super-2 number, since 2×218971900² = 95897385979220000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 218971900.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2700 + ... + 21100.

It is an arithmetic number, because the mean of its divisors is an integer number (7986468).

Almost surely, 2^218971900 is an apocalyptic number.

218971900 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 218971900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287512848).

218971900 is an abundant number, since it is smaller than the sum of its proper divisors (356053796).

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

218971900 is a wasteful number, since it uses less digits than its factorization.

218971900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18439 (or 18432 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 218971900 is about 14797.6991454753. The cubic root of 218971900 is about 602.7392345516.

The spelling of 218971900 in words is "two hundred eighteen million, nine hundred seventy-one thousand, nine hundred".