81793197 has 12 divisors (see below), whose sum is σ = 118272960. Its totient is φ = 54470088.

The previous prime is 81793193. The next prime is 81793241. The reversal of 81793197 is 79139718.

It is not a de Polignac number, because 81793197 - 2² = 81793193 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81793193) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4978 + ... + 13724.

It is an arithmetic number, because the mean of its divisors is an integer number (9856080).

Almost surely, 2^81793197 is an apocalyptic number.

It is an amenable number.

81793197 is a deficient number, since it is larger than the sum of its proper divisors (36479763).

81793197 is a wasteful number, since it uses less digits than its factorization.

81793197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9792 (or 9789 counting only the distinct ones).

The product of its digits is 95256, while the sum is 45.

The square root of 81793197 is about 9043.9591440917. The cubic root of 81793197 is about 434.0826168047.

The spelling of 81793197 in words is "eighty-one million, seven hundred ninety-three thousand, one hundred ninety-seven".