997788 has 24 divisors (see below), whose sum is σ = 2540160. Its totient is φ = 302320.

The previous prime is 997783. The next prime is 997793. The reversal of 997788 is 887799.

It is an interprime number because it is at equal distance from previous prime (997783) and next prime (997793).

It is a zygodrome in base 2 and base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997783) by changing a digit.

997788 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3648 + ... + 3911.

It is an arithmetic number, because the mean of its divisors is an integer number (105840).

2⁹⁹⁷⁷⁸⁸ is an apocalyptic number.

It is an amenable number.

997788 is an abundant number, since it is smaller than the sum of its proper divisors (1542372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

997788 is a wasteful number, since it uses less digits than its factorization.

997788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7577 (or 7575 counting only the distinct ones).

The product of its digits is 254016, while the sum is 48.

The square root of 997788 is about 998.8933877046. The cubic root of 997788 is about 99.9262122337.

It can be divided in two parts, 99 and 7788, that added together give a palindrome (7887).

The spelling of 997788 in words is "nine hundred ninety-seven thousand, seven hundred eighty-eight".