218139768 has 288 divisors, whose sum is σ = 767676000. Its totient is φ = 55883520.

The previous prime is 218139749. The next prime is 218139773. The reversal of 218139768 is 867931812.

It is a nude number because it is divisible by every one of its digits.

Its product of digits (145152) is a multiple of the sum of its prime divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2988180 + ... + 2988252.

Almost surely, 2^218139768 is an apocalyptic number.

218139768 is a gapful number since it is divisible by the number (28) 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 218139768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383838000).

218139768 is an abundant number, since it is smaller than the sum of its proper divisors (549536232).

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

218139768 is a wasteful number, since it uses less digits than its factorization.

218139768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 96 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 218139768 is about 14769.5554435467. Note that the first 3 decimals coincide. The cubic root of 218139768 is about 601.9747600739.

The spelling of 218139768 in words is "two hundred eighteen million, one hundred thirty-nine thousand, seven hundred sixty-eight".