81085197 has 4 divisors (see below), whose sum is σ = 108113600. Its totient is φ = 54056796.

The previous prime is 81085187. The next prime is 81085211. The reversal of 81085197 is 79158018.

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 not a de Polignac number, because 81085197 - 2⁶ = 81085133 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 (81085127) 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, 13514197 + ... + 13514202.

It is an arithmetic number, because the mean of its divisors is an integer number (27028400).

Almost surely, 2^81085197 is an apocalyptic number.

It is an amenable number.

81085197 is a deficient number, since it is larger than the sum of its proper divisors (27028403).

81085197 is a wasteful number, since it uses less digits than its factorization.

81085197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27028402.

The product of its (nonzero) digits is 20160, while the sum is 39.

The square root of 81085197 is about 9004.7319227171. The cubic root of 81085197 is about 432.8265158837.

The spelling of 81085197 in words is "eighty-one million, eighty-five thousand, one hundred ninety-seven".