915997 has 4 divisors (see below), whose sum is σ = 920800. Its totient is φ = 911196.

The previous prime is 915991. The next prime is 916031. The reversal of 915997 is 799519.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 799519 = 7 ⋅114217.

It is a cyclic number.

It is not a de Polignac number, because 915997 - 2⁷ = 915869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (915991) 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, 2103 + ... + 2500.

It is an arithmetic number, because the mean of its divisors is an integer number (230200).

2⁹¹⁵⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

915997 is a deficient number, since it is larger than the sum of its proper divisors (4803).

915997 is a wasteful number, since it uses less digits than its factorization.

915997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4802.

The product of its digits is 25515, while the sum is 40.

The square root of 915997 is about 957.0773218502. The cubic root of 915997 is about 97.1176169184.

The spelling of 915997 in words is "nine hundred fifteen thousand, nine hundred ninety-seven".