81352197 has 12 divisors (see below), whose sum is σ = 117586924. Its totient is φ = 54198720.

The previous prime is 81352189. The next prime is 81352199. The reversal of 81352197 is 79125318.

It can be written as a sum of positive squares in 2 ways, for example, as 72743841 + 8608356 = 8529^2 + 2934^2 .

It is not a de Polignac number, because 81352197 - 2³ = 81352189 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 (81352199) 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, 25047 + ... + 28107.

Almost surely, 2^81352197 is an apocalyptic number.

It is an amenable number.

81352197 is a deficient number, since it is larger than the sum of its proper divisors (36234727).

81352197 is a wasteful number, since it uses less digits than its factorization.

81352197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6020 (or 6017 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 81352197 is about 9019.5452767864. The cubic root of 81352197 is about 433.3010705106.

The spelling of 81352197 in words is "eighty-one million, three hundred fifty-two thousand, one hundred ninety-seven".