918997 has 4 divisors (see below), whose sum is σ = 931660. Its totient is φ = 906336.

The previous prime is 918989. The next prime is 919013. The reversal of 918997 is 799819.

918997 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: 799819 = 101 ⋅7919.

It can be written as a sum of positive squares in 2 ways, for example, as 269361 + 649636 = 519^2 + 806^2 .

It is a cyclic number.

It is not a de Polignac number, because 918997 - 2³ = 918989 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (918947) 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, 6222 + ... + 6367.

It is an arithmetic number, because the mean of its divisors is an integer number (232915).

2⁹¹⁸⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

918997 is a deficient number, since it is larger than the sum of its proper divisors (12663).

918997 is a wasteful number, since it uses less digits than its factorization.

918997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12662.

The product of its digits is 40824, while the sum is 43.

The square root of 918997 is about 958.6433121866. The cubic root of 918997 is about 97.2235253280.

The spelling of 918997 in words is "nine hundred eighteen thousand, nine hundred ninety-seven".