19997312 has 16 divisors (see below), whose sum is σ = 39838650. Its totient is φ = 9998592.

The previous prime is 19997297. The next prime is 19997317. The reversal of 19997312 is 21379991.

It can be written as a sum of positive squares in only one way, i.e., 19855936 + 141376 = 4456^2 + 376^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a self number, because there is not a number n which added to its sum of digits gives 19997312.

It is not an unprimeable number, because it can be changed into a prime (19997317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77987 + ... + 78242.

Almost surely, 2^19997312 is an apocalyptic number.

It is an amenable number.

19997312 is a deficient number, since it is larger than the sum of its proper divisors (19841338).

19997312 is an equidigital number, since it uses as much as digits as its factorization.

19997312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156243 (or 156231 counting only the distinct ones).

The product of its digits is 30618, while the sum is 41.

The square root of 19997312 is about 4471.8354173650. The cubic root of 19997312 is about 271.4296005237.

The spelling of 19997312 in words is "nineteen million, nine hundred ninety-seven thousand, three hundred twelve".