997777 has 8 divisors (see below), whose sum is σ = 1107072. Its totient is φ = 891600.

The previous prime is 997769. The next prime is 997783. The reversal of 997777 is 777799.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 997777 - 2³ = 997769 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (997727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73 + ... + 1414.

It is an arithmetic number, because the mean of its divisors is an integer number (138384).

2⁹⁹⁷⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

997777 is a deficient number, since it is larger than the sum of its proper divisors (109295).

997777 is a wasteful number, since it uses less digits than its factorization.

997777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1559.

The product of its digits is 194481, while the sum is 46.

The square root of 997777 is about 998.8878815963. The cubic root of 997777 is about 99.9258450240.

The spelling of 997777 in words is "nine hundred ninety-seven thousand, seven hundred seventy-seven".