997728489 has 16 divisors (see below), whose sum is σ = 1485552000. Its totient is φ = 661806288.

The previous prime is 997728469. The next prime is 997728509. The reversal of 997728489 is 984827799.

997728489 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (997728469) and next prime (997728509).

It is not a de Polignac number, because 997728489 - 2¹² = 997724393 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (997728439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87474 + ... + 98219.

It is an arithmetic number, because the mean of its divisors is an integer number (92847000).

Almost surely, 2^997728489 is an apocalyptic number.

It is an amenable number.

997728489 is a deficient number, since it is larger than the sum of its proper divisors (487823511).

997728489 is a wasteful number, since it uses less digits than its factorization.

997728489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185901 (or 185895 counting only the distinct ones).

The product of its digits is 18289152, while the sum is 63.

The square root of 997728489 is about 31586.8404402846. The cubic root of 997728489 is about 999.2422556352.

The spelling of 997728489 in words is "nine hundred ninety-seven million, seven hundred twenty-eight thousand, four hundred eighty-nine".