81271097 has 4 divisors (see below), whose sum is σ = 81293940. Its totient is φ = 81248256.

The previous prime is 81271063. The next prime is 81271111. The reversal of 81271097 is 79017218.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 23145721 + 58125376 = 4811^2 + 7624^2 .

It is a cyclic number.

It is not a de Polignac number, because 81271097 - 2¹⁶ = 81205561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81271297) 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, 4808 + ... + 13625.

It is an arithmetic number, because the mean of its divisors is an integer number (20323485).

Almost surely, 2^81271097 is an apocalyptic number.

It is an amenable number.

81271097 is a deficient number, since it is larger than the sum of its proper divisors (22843).

81271097 is a wasteful number, since it uses less digits than its factorization.

81271097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22842.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 81271097 is about 9015.0483637083. The cubic root of 81271097 is about 433.1570367010.

The spelling of 81271097 in words is "eighty-one million, two hundred seventy-one thousand, ninety-seven".