218007990 has 64 divisors (see below), whose sum is σ = 582681600. Its totient is φ = 58002912.

The previous prime is 218007967. The next prime is 218007991. The reversal of 218007990 is 99700812.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218007991) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 193569 + ... + 194691.

It is an arithmetic number, because the mean of its divisors is an integer number (9104400).

Almost surely, 2^218007990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218007990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (291340800).

218007990 is an abundant number, since it is smaller than the sum of its proper divisors (364673610).

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

218007990 is a wasteful number, since it uses less digits than its factorization.

218007990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1858 (or 1852 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 218007990 is about 14765.0936332961. The cubic root of 218007990 is about 601.8535182209.

The spelling of 218007990 in words is "two hundred eighteen million, seven thousand, nine hundred ninety".