997991222 has 8 divisors (see below), whose sum is σ = 1585044936. Its totient is φ = 469642912.

The previous prime is 997991221. The next prime is 997991233. The reversal of 997991222 is 222199799.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997991221) 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 3 ways as a sum of consecutive naturals, for example, 14676308 + ... + 14676375.

It is an arithmetic number, because the mean of its divisors is an integer number (198130617).

Almost surely, 2^997991222 is an apocalyptic number.

997991222 is a deficient number, since it is larger than the sum of its proper divisors (587053714).

997991222 is a wasteful number, since it uses less digits than its factorization.

997991222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29352702.

The product of its digits is 367416, while the sum is 50.

The square root of 997991222 is about 31590.9990661897. Note that the first 3 decimals coincide. The cubic root of 997991222 is about 999.3299584780.

The spelling of 997991222 in words is "nine hundred ninety-seven million, nine hundred ninety-one thousand, two hundred twenty-two".