81017197 has 4 divisors (see below), whose sum is σ = 85281280. Its totient is φ = 76753116.

The previous prime is 81017191. The next prime is 81017221. The reversal of 81017197 is 79171018.

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.

It is a cyclic number.

It is not a de Polignac number, because 81017197 - 2¹⁵ = 80984429 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 (81017191) 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, 2132013 + ... + 2132050.

It is an arithmetic number, because the mean of its divisors is an integer number (21320320).

Almost surely, 2^81017197 is an apocalyptic number.

It is an amenable number.

81017197 is a deficient number, since it is larger than the sum of its proper divisors (4264083).

81017197 is a wasteful number, since it uses less digits than its factorization.

81017197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4264082.

The product of its (nonzero) digits is 3528, while the sum is 34.

The square root of 81017197 is about 9000.9553381849. The cubic root of 81017197 is about 432.7054891303.

The spelling of 81017197 in words is "eighty-one million, seventeen thousand, one hundred ninety-seven".