997991216 has 20 divisors (see below), whose sum is σ = 1934826312. Its totient is φ = 498681216.

The previous prime is 997991213. The next prime is 997991221. The reversal of 997991216 is 612199799.

997991216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (997991213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7691 + ... + 45333.

Almost surely, 2^997991216 is an apocalyptic number.

It is an amenable number.

997991216 is a deficient number, since it is larger than the sum of its proper divisors (936835096).

997991216 is a wasteful number, since it uses less digits than its factorization.

997991216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39308 (or 39302 counting only the distinct ones).

The product of its digits is 551124, while the sum is 53.

The square root of 997991216 is about 31590.9989712260. The cubic root of 997991216 is about 999.3299564753.

The spelling of 997991216 in words is "nine hundred ninety-seven million, nine hundred ninety-one thousand, two hundred sixteen".