218080997 has 4 divisors (see below), whose sum is σ = 223975116. Its totient is φ = 212186880.

The previous prime is 218080991. The next prime is 218081023. The reversal of 218080997 is 799080812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 208340356 + 9740641 = 14434^2 + 3121^2 .

It is a cyclic number.

It is not a de Polignac number, because 218080997 - 2¹⁰ = 218079973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218080991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2947004 + ... + 2947077.

It is an arithmetic number, because the mean of its divisors is an integer number (55993779).

Almost surely, 2^218080997 is an apocalyptic number.

It is an amenable number.

218080997 is a deficient number, since it is larger than the sum of its proper divisors (5894119).

218080997 is an equidigital number, since it uses as much as digits as its factorization.

218080997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5894118.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 218080997 is about 14767.5657100282. The cubic root of 218080997 is about 601.9206940705.

The spelling of 218080997 in words is "two hundred eighteen million, eighty thousand, nine hundred ninety-seven".