218187509329 has 8 divisors (see below), whose sum is σ = 223518247848. Its totient is φ = 212857203840.

The previous prime is 218187509297. The next prime is 218187509333. The reversal of 218187509329 is 923905781812.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 19581804225 + 198605705104 = 139935^2 + 445652^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 218187509329 - 2⁵ = 218187509297 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 218187509329.

It is not an unprimeable number, because it can be changed into a prime (218187509369) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1065259 + ... + 1253455.

It is an arithmetic number, because the mean of its divisors is an integer number (27939780981).

Almost surely, 2^218187509329 is an apocalyptic number.

It is an amenable number.

218187509329 is a deficient number, since it is larger than the sum of its proper divisors (5330738519).

218187509329 is a wasteful number, since it uses less digits than its factorization.

218187509329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216515.

The product of its (nonzero) digits is 2177280, while the sum is 55.

The spelling of 218187509329 in words is "two hundred eighteen billion, one hundred eighty-seven million, five hundred nine thousand, three hundred twenty-nine".