997189218 has 20 divisors (see below), whose sum is σ = 2234442870. Its totient is φ = 332396352.

The previous prime is 997189211. The next prime is 997189229. The reversal of 997189218 is 812981799.

It can be written as a sum of positive squares in only one way, i.e., 717864849 + 279324369 = 26793^2 + 16713^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (997189211) 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 9 ways as a sum of consecutive naturals, for example, 3077583 + ... + 3077906.

Almost surely, 2^997189218 is an apocalyptic number.

997189218 is an abundant number, since it is smaller than the sum of its proper divisors (1237253652).

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

997189218 is a wasteful number, since it uses less digits than its factorization.

997189218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6155503 (or 6155494 counting only the distinct ones).

The product of its digits is 653184, while the sum is 54.

The square root of 997189218 is about 31578.3029626356. The cubic root of 997189218 is about 999.0621934605.

The spelling of 997189218 in words is "nine hundred ninety-seven million, one hundred eighty-nine thousand, two hundred eighteen".