997719 has 4 divisors (see below), whose sum is σ = 1330296. Its totient is φ = 665144.

The previous prime is 997699. The next prime is 997727. The reversal of 997719 is 917799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 917799 = 3 ⋅305933.

It is a cyclic number.

It is not a de Polignac number, because 997719 - 2⁸ = 997463 is a prime.

It is a super-2 number, since 2×997719² = 1990886405922, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166284 + ... + 166289.

It is an arithmetic number, because the mean of its divisors is an integer number (332574).

2⁹⁹⁷⁷¹⁹ is an apocalyptic number.

997719 is a deficient number, since it is larger than the sum of its proper divisors (332577).

997719 is a wasteful number, since it uses less digits than its factorization.

997719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332576.

The product of its digits is 35721, while the sum is 42.

The square root of 997719 is about 998.8588488871. The cubic root of 997719 is about 99.9239087826.

The spelling of 997719 in words is "nine hundred ninety-seven thousand, seven hundred nineteen".