219868509 has 16 divisors (see below), whose sum is σ = 335657088. Its totient is φ = 125406912.

The previous prime is 219868499. The next prime is 219868511. The reversal of 219868509 is 905868912.

It is a happy number.

It is not a de Polignac number, because 219868509 - 2⁹ = 219867997 is a prime.

It is a super-2 number, since 2×219868509² = 96684322499766162, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (219868529) 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 15 ways as a sum of consecutive naturals, for example, 2299 + ... + 21095.

It is an arithmetic number, because the mean of its divisors is an integer number (20978568).

Almost surely, 2^219868509 is an apocalyptic number.

It is an amenable number.

219868509 is a deficient number, since it is larger than the sum of its proper divisors (115788579).

219868509 is a wasteful number, since it uses less digits than its factorization.

219868509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19364.

The product of its (nonzero) digits is 311040, while the sum is 48.

The square root of 219868509 is about 14827.9637509673. The cubic root of 219868509 is about 603.5607790619.

It can be divided in two parts, 2198 and 68509, that added together give a palindrome (70707).

The spelling of 219868509 in words is "two hundred nineteen million, eight hundred sixty-eight thousand, five hundred nine".