218947680 has 432 divisors, whose sum is σ = 907517520. Its totient is φ = 47867904.

The previous prime is 218947679. The next prime is 218947681. The reversal of 218947680 is 86749812.

218947680 is a `hidden beast` number, since 21 + 89 + 476 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (218947679) and next prime (218947681).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218947681) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2046187 + ... + 2046293.

It is an arithmetic number, because the mean of its divisors is an integer number (2100735).

Almost surely, 2^218947680 is an apocalyptic number.

218947680 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 218947680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (453758760).

218947680 is an abundant number, since it is smaller than the sum of its proper divisors (688569840).

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

218947680 is a wasteful number, since it uses less digits than its factorization.

218947680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 218947680 is about 14796.8807523748. The cubic root of 218947680 is about 602.7170111788.

The spelling of 218947680 in words is "two hundred eighteen million, nine hundred forty-seven thousand, six hundred eighty".