997638 has 8 divisors (see below), whose sum is σ = 1995288. Its totient is φ = 332544.

The previous prime is 997637. The next prime is 997649. The reversal of 997638 is 836799.

It is a happy number.

997638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

997638 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 997638.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 997638.

It is not an unprimeable number, because it can be changed into a prime (997637) 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, 83131 + ... + 83142.

It is an arithmetic number, because the mean of its divisors is an integer number (249411).

2⁹⁹⁷⁶³⁸ is an apocalyptic number.

997638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

997638 is a wasteful number, since it uses less digits than its factorization.

997638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166278.

The product of its digits is 81648, while the sum is 42.

The square root of 997638 is about 998.8183017947. The cubic root of 997638 is about 99.9212045958.

The spelling of 997638 in words is "nine hundred ninety-seven thousand, six hundred thirty-eight".