997181 has 4 divisors (see below), whose sum is σ = 999552. Its totient is φ = 994812.

The previous prime is 997163. The next prime is 997201. The reversal of 997181 is 181799.

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: 181799 = 137 ⋅1327.

It is a cyclic number.

It is not a de Polignac number, because 997181 - 2¹⁰ = 996157 is a prime.

It is a super-2 number, since 2×997181² = 1988739893522, which contains 22 as substring.

It is a Duffinian number.

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 997181.

It is not an unprimeable number, because it can be changed into a prime (997111) 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, 365 + ... + 1458.

It is an arithmetic number, because the mean of its divisors is an integer number (249888).

2⁹⁹⁷¹⁸¹ is an apocalyptic number.

It is an amenable number.

997181 is a deficient number, since it is larger than the sum of its proper divisors (2371).

997181 is a wasteful number, since it uses less digits than its factorization.

997181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2370.

The product of its digits is 4536, while the sum is 35.

The square root of 997181 is about 998.5895052523. The cubic root of 997181 is about 99.9059448974.

The spelling of 997181 in words is "nine hundred ninety-seven thousand, one hundred eighty-one".