81327897 has 18 divisors (see below), whose sum is σ = 136653738. Its totient is φ = 46472832.

The previous prime is 81327871. The next prime is 81327937. The reversal of 81327897 is 79872318.

It can be written as a sum of positive squares in only one way, i.e., 47734281 + 33593616 = 6909^2 + 5796^2 .

It is not a de Polignac number, because 81327897 - 2⁶ = 81327833 is a prime.

It is a super-2 number, since 2×81327897² = 13228453660885218, which contains 22 as substring.

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 not an unprimeable number, because it can be changed into a prime (81327097) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 91768 + ... + 92649.

Almost surely, 2^81327897 is an apocalyptic number.

It is an amenable number.

81327897 is a deficient number, since it is larger than the sum of its proper divisors (55325841).

81327897 is a wasteful number, since it uses less digits than its factorization.

81327897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184437 (or 184427 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 81327897 is about 9018.1981016165. The cubic root of 81327897 is about 433.2579236957.

The spelling of 81327897 in words is "eighty-one million, three hundred twenty-seven thousand, eight hundred ninety-seven".