997728311 has 4 divisors (see below), whose sum is σ = 999280632. Its totient is φ = 996175992.

The previous prime is 997728253. The next prime is 997728337. The reversal of 997728311 is 113827799.

997728311 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 113827799 = 37 ⋅3076427.

It is a cyclic number.

It is not a de Polignac number, because 997728311 - 2¹⁴ = 997711927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997728811) 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, 775196 + ... + 776481.

It is an arithmetic number, because the mean of its divisors is an integer number (249820158).

Almost surely, 2^997728311 is an apocalyptic number.

997728311 is a deficient number, since it is larger than the sum of its proper divisors (1552321).

997728311 is a wasteful number, since it uses less digits than its factorization.

997728311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1552320.

The product of its digits is 190512, while the sum is 47.

The square root of 997728311 is about 31586.8376226554. The cubic root of 997728311 is about 999.2421962118.

The spelling of 997728311 in words is "nine hundred ninety-seven million, seven hundred twenty-eight thousand, three hundred eleven".