81797189 has 8 divisors (see below), whose sum is σ = 84772608. Its totient is φ = 78842880.

The previous prime is 81797167. The next prime is 81797201. The reversal of 81797189 is 98179718.

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 81797189 - 2⁸ = 81796933 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 (81097189) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2834 + ... + 13100.

It is an arithmetic number, because the mean of its divisors is an integer number (10596576).

Almost surely, 2^81797189 is an apocalyptic number.

It is an amenable number.

81797189 is a deficient number, since it is larger than the sum of its proper divisors (2975419).

81797189 is a wasteful number, since it uses less digits than its factorization.

81797189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10555.

The product of its digits is 254016, while the sum is 50.

The square root of 81797189 is about 9044.1798412017. The cubic root of 81797189 is about 434.0896786374.

The spelling of 81797189 in words is "eighty-one million, seven hundred ninety-seven thousand, one hundred eighty-nine".