897991 has 8 divisors (see below), whose sum is σ = 962064. Its totient is φ = 835200.

The previous prime is 897983. The next prime is 898013. The reversal of 897991 is 199798.

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 897991 - 2³ = 897983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (897931) 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 7 ways as a sum of consecutive naturals, for example, 1456 + ... + 1978.

It is an arithmetic number, because the mean of its divisors is an integer number (120258).

2⁸⁹⁷⁹⁹¹ is an apocalyptic number.

897991 is a deficient number, since it is larger than the sum of its proper divisors (64073).

897991 is a wasteful number, since it uses less digits than its factorization.

897991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641.

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

The square root of 897991 is about 947.6238705309. The cubic root of 897991 is about 96.4770453782.

The spelling of 897991 in words is "eight hundred ninety-seven thousand, nine hundred ninety-one".